I don't know why I found this video or I'm answering your question two years later but... All world record attempts stop at the boomerang gun. The reason I think because they never tell me I either... There are four basic guns the first two are the green dots the next two are the boomerangs the next two are black spinnies and the 4th one is the arrows that shoot straight. They all actually do the same damage except for the green dots gun. The problem is the black spinnies Gun. Most of the game is in narrow corridors and the black spinnies bounce off the walls. You could upgrade all the way but then you would have to avoid all the red guns downgrades when it would be just easier to stay with the boomerang gun and not worry about it. Plus you would have to wait for the upgrades and you wouldn't be able to use the third black spinning gun
What's up with wanting to stick with the boomerang bullets? Aren't they weaker?
I don't know why I found this video or I'm answering your question two years later but...
All world record attempts stop at the boomerang gun. The reason I think because they never tell me I either... There are four basic guns the first two are the green dots the next two are the boomerangs the next two are black spinnies and the 4th one is the arrows that shoot straight. They all actually do the same damage except for the green dots gun.
The problem is the black spinnies Gun. Most of the game is in narrow corridors and the black spinnies bounce off the walls. You could upgrade all the way but then you would have to avoid all the red guns downgrades when it would be just easier to stay with the boomerang gun and not worry about it. Plus you would have to wait for the upgrades and you wouldn't be able to use the third black spinning gun