My guess wouldve been "AH" stands for "Activate Hazard" but I didnt want to say it in the video and give you guys a false sense of authority on the subject. I'll update someday if i get the definitive answer
Thats bad that your network doesnt know. Every network should have a direct line of contact with youtube like mine did. if you google youtube verification checkmark though. there is an application that you can submit yourself to youtube. You definitely have over passed the qualifications
You can see him on Kunckle's Hydrocity Act 2 leaderboard, with a time of 0:37. It's only possible with a glitch (That I shamelessly exploited too), so a video is definitively coming. If you're interested, DarkSpineSonic uploaded a video of that glitch.
Those "windows" in Lava Reef/Hidden Palace Zone are suppose to be the murals prophesying Sonic's battle with Robotnik at the end of Sonic 3 & Knuckles. That area is taken directly from Hidden Palace Zone and they probably intended to use that area due to the iconic murals.
gmaster2647 You do with all three characters, it's just not a separate location. Knuckles goes through more of it though and has his boss battle and the Emerald Altar complete with the lifeless Super Emeralds.
+Scrade McRabbitSomethingOrOther Wouldn't that mean Sonic 3&K is also not canon? After all, you need the super emeralds to get the final stage and true ending
No. AH, AL, BH, BL are A and B layer high and low path swappers. They have the same exact purpose they did in Sonic 1, Sonic 2, and Sonic 3 & Knuckles, except in the older games when they appeared in debug mode they appeared as a series of four non-moving static rings. They have nothing to do with what "layer" sonic is on; they swap between collision sets A and B. Every tile in the game has two sets of collision and that's how loops, secret passages, joining/diverging pathways, etc work. The "high" and "low" variants determine the sprite priority of sonic (behind or in front of the foreground), but this is purely visual.
8:53 looks like the knuckles' boss fight room from S3K And also, the debug mode in this game is literally the same as in the previous genesis games, the spin and layer triggers also appear in s2 - s3k debugs.
The debug in this game is definitely scaled down. You can't place a lot of the objects from the stages (like crumbling floors for example). There's rings, item boxes, enemies, special stage rings, checkpoints, and the goal
Must be awkward when you're trying to gather footage of the game for a video and the Switch keeps giving you those "Your Friend is playing X Game" messages.
6:10 "You don't get to have any World 1-2 shenanigans!" Mirage Saloon 2 with Knuckles begs to differ, you can climb over the final wall and skip the boss!
That unused area from lava reef looks like hidden palace zone from sonic and Knuckles, I think that the glitchy tiles are probably the murals with super sonic fighting eggman from S&K. They probably removed the picture from the game and then it just turned into a glitchy mess because of it
Using the "Child's toy", I actually managed to crash my game. EDIT: I also managed to softlock it at the end by putting a Ring-box in supersonic's flight path.
John Doe keep in mind that classic sonic is strictly 2D and modern sonic is strictly 3D in forces modern is no longer gonna have 2D segments in his stages
Bro, I can honestly and firmly say that you always... keep pushing your Boundaries...hehehe. Your content has gotten so much better so quickly. Great stuff brother! Keep it up! Is there any chance you'd do a Boundary break for Ultimate Marvel Vs Capcom 3? I'd share this video with my community in a heart beat! Anyway, thanks for all of the amazing content!
8:49 that's the room where you would normally battle knuckles but it was unused. The makers of sonic mania did say they ported most if not all the stages in sonic and edited them a bit unlike the new stages
In press garden act 1, if you go below the area where the player starts the level, you should reach an open area that is completely empty except of an invertet HELLO message on the wall. Obviously left there by the developers for people using the debug menu.
Thanks Shesez for not giving away any major bosses :D I wanted to watch the episode but I haven't beat it completely yet due to time. Your so good to us!
Wow, I'm impressed! The studio's faithfulness to the original, even in background things like the lava and fish. Can't wait to play this and scope out every area like I did as a kid with the original games.
OMG! I've done that sign trick before in the original Sonic 1 & 2 mobile ports! And it was so fun. I found a sprite test far off the edge of Chemical Plant 2.
The guy that did the intro did a real good job. He made it look like it was being recorded onto a vhs tape with the soft image and the color fringing. Guess a throwback look to a throwback game. Great attention to detail.
Those Eggman kill/push tiles are a stroke of genius on the developer's part. I love how clever it is and using Eggman's face makes it super cheeky too, well done Sonic Mania.
8:52 My guess is that those messed up tiles on the walls were suppose to be the Super Sonic murals that were in Lava Reef zone in the original Sonic 3&K. They look about the same size.
Thank you Christian Whitehead. I mean Muslim Blackface. Dude did some great work but jesus christ his name is so ridiculous. Must be super awkward for him to greet a black person. "Hi! I'm Christian Whitehead!" "YOU WHAT!?"
i love these vids they inspire me to somehow break the games i own. one time i got the tank in halo 2 through a tunnel too small for it. best ending to that level i could ever ask for. btw the level was the city. keep up the good work please!
Hey Shesez, would you be able to do a boundary break video on the game "Silent Hills P.T"? That would be really interesting to se whats behind the dors and how the whole map looks in zoomed out view. Thanks for making great videos man and keep up the good work!
AL = Action Layer - As close as the foreground can get. BL = Background Layer - Switches the player to the back part of the ground to let you pass a loop de loop. AH = Active Hazard - An active object that can make you take damage when coming into contact with it. S = Spin - Automatically switches the player into it's spin-ball form.
This is so awesome! I totally need to see if I can get a hold of this game! (...After Christmas when I get my PS4... Maybe my birthday, maybe Ratchet and Clank too? February birthdays kinda suck without video games...)
0:03 Tails' laugh is actually a high-pitched version of the sound that plays when you enter and exit the Special Stages in Sonic the Hedgehog (1991), Sonic the Hedgehog 2 (1992) and Sonic the Hedgehog 3 and Knuckles (1994), and at 0:07, Sonic's scream is actually a high-pitched and slowed down version of the sound that plays when you land on spikes in Sonic the Hedgehog (1991), Sonic the Hedgehog 2 (1992) and Sonic the Hedgehog 3 and Knuckles (1994).
The section at 8:49 was supposed to be the Knuckles vs Sonic fight from Sonic 3 & Knuckles. I’m sure someone’s pointed it out. It’s weird because the glitched tiles you mentioned are supposed to be a weird hieroglyphic picture of Super Sonic vs the S3&K final boss in space. You can kinda make out the shapes from the glitched tiles. The next room was supposed to be the super emerald room where the emeralds were kept in S3&K.
Another thing I found was that in green hill zone act 2 if u use one of those boxes with the 2 arrows the game puts the totem background and the camera gets stuck in 1 position
8:56 That picture is actually a glitched up version of the mural from S 3&K's Knuckles boss fight, you know, the one depicting Super Sonic fighting Eggman for the Master Emerald
That's awesome there is a debug mode in this. I used to play with the debug mode in the first few games back in the genesis all the time, and explore how the game was put together. Neat how this game shows you where collision triggers for various actions are.
This was a really fast turn around! Nice of Sega to give you that super-advanced copy so you can get their free marketing done quickly, huh? :D Haha, just kidding! Really cool!
I can explain the "window" area in lava reef zone act 2 boss area. The delevopers actually copied the *ENTIRE* lava reef act 2 boss arena from sonic & knuckles's hidden palace zone. After the developers finished the heavy rider and the heavy king's boss arenas, they were left with extra space that were remnants of the original hidden palace zone from sonic & knuckles. The developers were like: " nah whatever. I will not waste my time deleting the extra space. Instead I will just block it of so no one will ever find it!" Turns out that some people *DID* find it. The area with the windows was actually the boss arena for the the famous sonic VS knuckles boss fight. There was actually a whole other set of chaos emeralds that the developers didn't bother to delete. The windows were actually supposed to be sprites of rurals from the original sonic & knuckles's hidden palace zone. But since sonic mania did not have the rural sprites. The rurals instead became a jumble of other sprites that arranged themselves to look like windows. I hope that this comment has help you understand what that mysterious area is for. Thank me later.
The doctor robot nick symbols are also how crushing works, in certain walls were your expected to get crushed, they put the doctor robot nick symbols there so die instantly, or, 'get crushed'
In green hill zone there is a point where you are under a water fall and a perana is shown in sight and is springing and down also there are rings too so that means one of the level designers left that in for the player to find out!
My guess wouldve been "AH" stands for "Activate Hazard" but I didnt want to say it in the video and give you guys a false sense of authority on the subject. I'll update someday if i get the definitive answer
I’m the first reply here. Someone should’ve replied 5 years ago
@@SunBurntfishvrgt lol true
AL = Action Layer
Larry you dont have a verified checkmark yet? Why the wait?
I have no idea how to get one dude, and even my network (Disney) has no clue :(
Thats bad that your network doesnt know. Every network should have a direct line of contact with youtube like mine did.
if you google youtube verification checkmark though. there is an application that you can submit yourself to youtube. You definitely have over passed the qualifications
i think its alpha male
It might of changed since, but on one of my other accounts, I got a checkmark by verifying myself with a mobile phone number.
7:45 A+Start playing Sonic Mania, now I may be thinking to much into it but I think I see a son of a glitch episode in the making
Link Tahuterasu Spirit just commented that xF
You can see him on Kunckle's Hydrocity Act 2 leaderboard, with a time of 0:37. It's only possible with a glitch (That I shamelessly exploited too), so a video is definitively coming. If you're interested, DarkSpineSonic uploaded a video of that glitch.
Link Tahuterasu Spirit oh yes!
Link Tahuterasu Spirit Shezes Is Friend Of A+Start
Vicente Masotti I’m well aware of that
7:45 A+start cameo appearance
Yup!
Those "windows" in Lava Reef/Hidden Palace Zone are suppose to be the murals prophesying Sonic's battle with Robotnik at the end of Sonic 3 & Knuckles. That area is taken directly from Hidden Palace Zone and they probably intended to use that area due to the iconic murals.
Also I read that in Knuckles' playthrough you get to visit Hidden Palace Zone. I don't know how extensive it is, but yeah.
gmaster2647 You do with all three characters, it's just not a separate location. Knuckles goes through more of it though and has his boss battle and the Emerald Altar complete with the lifeless Super Emeralds.
But I thought the Super Emeralds weren't canon?
+Scrade McRabbitSomethingOrOther
Wouldn't that mean Sonic 3&K is also not canon? After all, you need the super emeralds to get the final stage and true ending
No, you don't. You can reach Doomsday with just the Chaos Emeralds.
I've got a feeling AH stands for "Activate Hazard" or something like that
i think its "advance hazard"
bc its in the advance layer
@@leannehayes2364 There is no Advance Layer
It’s action hazard
No. AH, AL, BH, BL are A and B layer high and low path swappers. They have the same exact purpose they did in Sonic 1, Sonic 2, and Sonic 3 & Knuckles, except in the older games when they appeared in debug mode they appeared as a series of four non-moving static rings. They have nothing to do with what "layer" sonic is on; they swap between collision sets A and B. Every tile in the game has two sets of collision and that's how loops, secret passages, joining/diverging pathways, etc work. The "high" and "low" variants determine the sprite priority of sonic (behind or in front of the foreground), but this is purely visual.
@@NillKitty Huh. The More You Know
At 8:52, it appears to be a glitchy version of the prophecy mural/where you fight knuckkes as sonic from 3&K. Thought that was interesting.
SONIC CLEARED ACT 2 SON- SO- SONI- SONIC CL- SO- SON- SO- SONIC CLEARED A- SO- SO-
the way the music stutters and restarts is gold
XD
I thought you were having a stroke
xFractur3 LMAO
That was me abusing debug mode the other day.
69th like (#3)
8:53 looks like the knuckles' boss fight room from S3K
And also, the debug mode in this game is literally the same as in the previous genesis games, the spin and layer triggers also appear in s2 - s3k debugs.
S3& knuckles featuring Knuckles from the Knuckles may Chuckle series
its a me nikitosnekit so it doesn't appear in. sonic 1
The debug in this game is definitely scaled down. You can't place a lot of the objects from the stages (like crumbling floors for example). There's rings, item boxes, enemies, special stage rings, checkpoints, and the goal
Its boring in this version
& Knuckles
Don't worry about it, Christian whitehead is notorious for never replying to anybody
TheAnimaldude55 lol
True
Must be awkward when you're trying to gather footage of the game for a video and the Switch keeps giving you those "Your Friend is playing X Game" messages.
I don't have a Switch yet..is there really no way to disable those notifications?
Sato I'm pretty sure there is.
Should we really care what our friends are playing?! I wonder why Nintendo thought this would be a good idea to have on the Switch anyways!
Torrie Garvin well I guess I'll have no friends
Sato System Settings > Notifications > Friend Notifications
JESUS, YOU GOT THROUGH ACT 2 17 TIMES!!!!!
JESUS, YOU COUNTED??!?!
Jevron Freeman what does this mean
that means there are 18 acts
Mario Playthroughs 16 Whole acts unused lmao
welcome to act 19.
6:10 "You don't get to have any World 1-2 shenanigans!"
Mirage Saloon 2 with Knuckles begs to differ, you can climb over the final wall and skip the boss!
Holy shit, Give us a ''Sonic the hedgehog maker'' please, for the love of god! I want to make my own stages.
DID U KNOW THAT U CAN MAKE UR OWN SONIC STAGES IN A ROBLOX GAME CALLED CLASSIC SONIC SIMULATOR
Same
Same
search for the sonic studio project, it's amazing !
@@thiccdoge2002 bruh
That unused area from lava reef looks like hidden palace zone from sonic and Knuckles, I think that the glitchy tiles are probably the murals with super sonic fighting eggman from S&K. They probably removed the picture from the game and then it just turned into a glitchy mess because of it
Geez, a Boundary Break episode 3 days after the game's release? YOU'RE TOO SLOW!! Next time, get it before the game's even out.
Revegelance "shesez you're losing the race
Revegelance
Right.
(Juskiddingplzdontsueme)
pretty rude
Dude, it's a joke.
Idontknowhowtospace.
I'm guessing AH=Activate Hazard
Or advance hazard like advance layer
Maybe action hazard.
Close. It means 'Action Hazard'
I HAVE BEEN WAITING FOR THIS SO LONG!
"OH NO"~ Chuckles
Knucks & Knuckles featuring Knuckles from the Knuckles may Chuckle series
Nicholas B.
BUT WAIT! WE'RE HAVING A SPECIAL 2 FOR ONE SPECIAL!
"You can call me Knuckles," - Muscles McChuckles
i thought his name was Nipples the Enchilada
Shesez is friends with A+ start and they're both playing sonic mania,does that mean new A+ start video soon!??!?!?!?
It does. hold onto your butts for that one
@@BoundaryBreak XD
@@sth5sonicthehedgehogproduc144im from da future and they made a vid for sonic mania 5 years ago for sonic mania plus and for the original 6 years ago
those glitched wall sprites in lava reef zone look like they would have had that painting/mural from sonic 3 and knuckles when you fight knuckles
They are. That part's taken directly from Hidden Palace Zone in Sonic & knuckles
Using the "Child's toy", I actually managed to crash my game.
EDIT: I also managed to softlock it at the end by putting a Ring-box in supersonic's flight path.
Choking hazard for ages 3 and under
LOL
Are you russian?
I got a Sonic Mania ad before this video
JAK0B Wow! ISN'T THAT A COINCIDENCE!
STRANGE, ISN'T IT!
It plays ads based on the video (ex. Gaming ads for gaming videos)
JAK0B coinsidence? I think so.
Mist Surreal what about me getting shitty mobile gaming ads on every single video I watch even non gaming ones
Glad you did a video on this game so soon! Frozen Sonic was my favorite part
This gives high hopes for Forces. Even Arin (Speedwagon) likes this game!
Wilfred Cthulu doubt it. The half 3D half 2D style isn't fun.
John Doe a million other people disagree with you.
John Doe keep in mind that classic sonic is strictly 2D and modern sonic is strictly 3D in forces modern is no longer gonna have 2D segments in his stages
Doubt it, Totally different teams. Have nothing to do with each other
Link Tahuterasu Spirit But the demo has modern sonic have 2D segments...
Bro, I can honestly and firmly say that you always...
keep pushing your Boundaries...hehehe.
Your content has gotten so much better so quickly. Great stuff brother! Keep it up! Is there any chance you'd do a Boundary break for Ultimate Marvel Vs Capcom 3? I'd share this video with my community in a heart beat!
Anyway, thanks for all of the amazing content!
AH - Area Hazards? Just a thought...
8:49 that's the room where you would normally battle knuckles but it was unused. The makers of sonic mania did say they ported most if not all the stages in sonic and edited them a bit unlike the new stages
Vegeta Eating Chashu Pork yep
In press garden act 1, if you go below the area where the player starts the level, you should reach an open area that is completely empty except of an invertet HELLO message on the wall. Obviously left there by the developers for people using the debug menu.
Leon Babić lol wth youre right, even with sonic mania plus
Thanks Shesez for not giving away any major bosses :D I wanted to watch the episode but I haven't beat it completely yet due to time. Your so good to us!
6:29
"I was frozen today!"
Christopher Lloyd is the man
@ 8:56 super chaos emerald area with 7 gems as the supposed to be platforms. most likely was in development but not enough time
It is in the game on Knuckles path. What are you talking about there was no time if it was just copy pasted area from sonic 3?
Wow, I'm impressed! The studio's faithfulness to the original, even in background things like the lava and fish. Can't wait to play this and scope out every area like I did as a kid with the original games.
You mean Stealth's ability to rip assets from the ROMs into pretty much any format imaginable. This is fan game #71519 to use Sonic 1/2/3's assets.
I literally rewatched that intro animation several times- it's so cute!!
*Camera. You're too slow!*
👏🏻
OMG! I've done that sign trick before in the original Sonic 1 & 2 mobile ports! And it was so fun. I found a sprite test far off the edge of Chemical Plant 2.
Enjoyed the video but are we getting sonic heroes as well later on?
The guy that did the intro did a real good job. He made it look like it was being recorded onto a vhs tape with the soft image and the color fringing. Guess a throwback look to a throwback game. Great attention to detail.
That extra lava reef zone 3 it seems it is hidden palace zone from sonic & Knuckles
It is. With part of the boss fight from Act 2 minus the Death Egg in the background
7:44 Came from A+Start's video and that's REEEEEAL sneaky.
thanks for stopping by man!
You missed press garden's "Hello" At the bottom of the beggining in act 1
@Braxton Suire ua-cam.com/video/DGqi_BTU-Yg/v-deo.html
Cool video! I've just bought this game yesterday and I'm really glad with this.
AH = Activate Hazard?
Action hazard maybe
It is action hazard
The Stoopid Unikorn yeah maybe
Hoi gab
Those Eggman kill/push tiles are a stroke of genius on the developer's part. I love how clever it is and using Eggman's face makes it super cheeky too, well done Sonic Mania.
"Wow, we got this one out quick." Took the words right out of my mouth.
8:52 My guess is that those messed up tiles on the walls were suppose to be the Super Sonic murals that were in Lava Reef zone in the original Sonic 3&K. They look about the same size.
Sonic Maker, Nintendo, Sega, please, make it happen utilizing the mechanics we see in this video.
11:25 does anyone know the song name? From which game?
Thank you Christian Whitehead.
I mean Muslim Blackface.
Dude did some great work but jesus christ his name is so ridiculous.
Must be super awkward for him to greet a black person.
"Hi! I'm Christian Whitehead!"
"YOU WHAT!?"
Egg man you didn’t tell me you could fly!?
Can you please do Donkey Kong Country Returns? or Tropical Freeze?
i love these vids they inspire me to somehow break the games i own. one time i got the tank in halo 2 through a tunnel too small for it. best ending to that level i could ever ask for. btw the level was the city. keep up the good work please!
Your friends with A+Start?
Yep!
Shesez Wow i never knew that two of my favorite youtubers know each other
we actually run a side channel together where we talk about games! youtube search "Game Club Podcast"
Shesez ok
I've been waiting for another Arkham game boundary break for so long, it's hands down my favourite game series.
That was quick.
+RC-7593 Gotta go fast. ;)
I didn't expect this to be done this quickly. Nice.
Pretty cool that they even recreated that old debug mode, though.
You are friends? Andy from A+Start?
Hey Shesez, would you be able to do a boundary break video on the game "Silent Hills P.T"? That would be really interesting to se whats behind the dors and how the whole map looks in zoomed out view. Thanks for making great videos man and keep up the good work!
Please do Sonic Heroes next
ZePren GMD Sonic Heroes isn't for PS4. Its for the Xbox, PS2 and Gamecube.
Great job! Love these videos. Keep up the good work
Please do a Sonic Heroes Boundary Break!
The fish in Green Hill Zone have always done that sudden ricochet back up, even in the original Sonic 1.
Otherwise, great vid.
i asked this but PLEASE do Luigi's mansion dark moon
In Press Garden Zone Act 1, if you go a little bit into the act and then use debug mode to go up, there will be blocks spelling HELLO backwards.
The water hurts me
AL = Action Layer - As close as the foreground can get.
BL = Background Layer - Switches the player to the back part of the ground to let you pass a loop de loop.
AH = Active Hazard - An active object that can make you take damage when coming into contact with it.
S = Spin - Automatically switches the player into it's spin-ball form.
AH stands for either "AW HECK" or just "AAAH" because that's what you say when the ground falls from underneath you
What's the debug menu code in Sonic on NINTENDO SWITCH? because I have a Switch.
It was that code, but Sega patched it out. I'm sad too, don't worry.
Can you please do Splatoon 2?
MZ_ swag We need hacks lol
I GOT NOTICED BY SHESEZPAI
MZ_ swag Oh shit it's Splat Tim
Ace Abe oh shoot waddup
This is so awesome! I totally need to see if I can get a hold of this game! (...After Christmas when I get my PS4... Maybe my birthday, maybe Ratchet and Clank too? February birthdays kinda suck without video games...)
Just guess what ad I saw before this video
Handsaw [ESK] I wonder
Handsaw [ESK] You got bug eyes!
Handsaw [ESK] sonic mania
Handsaw [ESK]
You got an ad for Marvel's "The Defenders" on Netflix?
mario?
1:20 that’s because you have found sonic’s stage which is always placed above of knuckle’s stage
JoeyMan Plays Sonic Mania (PS4) Live Streams: ua-cam.com/play/PLGrP0T8BOZIACSpBt0MK65QkaG1xohE2O.html
After watching this video I'm actually glad I bought this game. So much fun seeing what others do in the game and playing it as well
the fact that I know there is a mean bean machine boss fight fills me with joy and tells me I need to buy this game.
I have a feeling this is going to be the next Game Club Podcast
0:03 Tails' laugh is actually a high-pitched version of the sound that plays when you enter and exit the Special Stages in Sonic the Hedgehog (1991), Sonic the Hedgehog 2 (1992) and Sonic the Hedgehog 3 and Knuckles (1994), and at 0:07, Sonic's scream is actually a high-pitched and slowed down version of the sound that plays when you land on spikes in Sonic the Hedgehog (1991), Sonic the Hedgehog 2 (1992) and Sonic the Hedgehog 3 and Knuckles (1994).
7:31 Nice Pun Shesez, Nice Pun
9:34 for some reason this glitch is in Sonic 2 and Sonic 1's mobile ports
The section at 8:49 was supposed to be the Knuckles vs Sonic fight from Sonic 3 & Knuckles. I’m sure someone’s pointed it out. It’s weird because the glitched tiles you mentioned are supposed to be a weird hieroglyphic picture of Super Sonic vs the S3&K final boss in space. You can kinda make out the shapes from the glitched tiles.
The next room was supposed to be the super emerald room where the emeralds were kept in S3&K.
Another thing I found was that in green hill zone act 2 if u use one of those boxes with the 2 arrows the game puts the totem background and the camera gets stuck in 1 position
The love for Sonic just oozes through this whole games - it's sooooo good.
8:56 That picture is actually a glitched up version of the mural from S 3&K's Knuckles boss fight, you know, the one depicting Super Sonic fighting Eggman for the Master Emerald
That's awesome there is a debug mode in this. I used to play with the debug mode in the first few games back in the genesis all the time, and explore how the game was put together. Neat how this game shows you where collision triggers for various actions are.
Wow the part where sonic slipped on that banana peel was SMOOTH AS HECK!!
This was a really fast turn around! Nice of Sega to give you that super-advanced copy so you can get their free marketing done quickly, huh? :D Haha, just kidding! Really cool!
0:00 Last Dinosaurs - Dominos
Get it? XD
I like how a+start appeared at 7:45
3:42 Actually, there is a pseudo-closeup on the title screen - and the island looks like Sonic’s Head! Did you know-tice?
8:51 I think that glitched "window" was supposed to be the prophecy thing seen in the knuckles battle in sonic &knuckles/s3&k
I want to see off camera secrets to ARMS because that game as so much detail in it, but you can never see it. So it be cool to see more of that world!
7:43 didn't know you were friends with the guy who does son of a glitch
I can explain the "window" area in lava reef zone act 2 boss area. The delevopers actually copied the *ENTIRE* lava reef act 2 boss arena from sonic & knuckles's hidden palace zone. After the developers finished the heavy rider and the heavy king's boss arenas, they were left with extra space that were remnants of the original hidden palace zone from sonic & knuckles. The developers were like: " nah whatever. I will not waste my time deleting the extra space. Instead I will just block it of so no one will ever find it!" Turns out that some people *DID* find it. The area with the windows was actually the boss arena for the the famous sonic VS knuckles boss fight. There was actually a whole other set of chaos emeralds that the developers didn't bother to delete. The windows were actually supposed to be sprites of rurals from the original sonic & knuckles's hidden palace zone. But since sonic mania did not have the rural sprites. The rurals instead became a jumble of other sprites that arranged themselves to look like windows. I hope that this comment has help you understand what that mysterious area is for. Thank me later.
Jumping piranha thing is from the original Sonic 1 for Sega Mega Drive, and it was jumping the same way how now it jumps in Sonic Mania.
8:45 actually that's the knuckles boss fight area from sonic & knuckles
'AH' stands for 'Action Hazard'. You might notice that it's often placed around platforms that collapse when Sonic touches them.
The doctor robot nick symbols are also how crushing works, in certain walls were your expected to get crushed, they put the doctor robot nick symbols there so die instantly, or, 'get crushed'
Whats up with a+Start in the left corner at about 7:35 ?
In green hill zone there is a point where you are under a water fall and a perana is shown in sight and is springing and down also there are rings too so that means one of the level designers left that in for the player to find out!