Green Hill Zone Act 1 - Sonic: 30 Day Project music

Sonic: 30 Day Project is a 2013-2014 romhack of Sonic the Hedgehog by Psychosk8r featuring abilities for Sonic, New layouts and art for most stages, a gimmick featuring finding an Emerald Monitor to be able to break a wall blocking the goalpost, and more.
I would link to the romhack, but all official links at this point seem to be dead.

[@EddyTheFox]

Sonic 1 Reboot - Green Hill Zone Act 1 (Day)

[@gamerlunayt]

First!