good game, great music choice, decent gameplay, decent level design and graphics but i find some things kinda off...
first of all, the warning panels are kinda garbage. They almost never display the correct warning! Half of the time it will say "pit" when there's actually an enemy or spikes in front of me, and i got a warning for "enemy" when there were actually pits! Please fix this.
second, the final fight with nytron was hard to understand (most other bosses were hard to understand too), it wasn't very clear that you could teleport or that you could dash through the purple rocks to get more rings. The final attack was also confusing, I didn't know you had to spam teleport.
speaking of bosses, the homing attack nearly never works except for nytron 2.0, there the homing attack worked fine
thirdly, grinding is broken, there is not really any sense of momentum but that doesn't matter much, but downward slanted rails are super broken, most of the time sonic is floating above the rail and you can't jump off it.
and finally, when you get hit during a boss battle, it can be very punishing, pushing you to the edge of the screen. In the fight with Egg Eskimo it gets especially tiring as you constantly get hit by spikes or the snowballs, so you almost never get the chance to attack.
btw i find subzero sector harder than vegestoria just saying you might want to change that. There's a pit in S.S that you cant jump over at a high speed.
also btw, why does the main menu change if you fail against the final boss, it is cool though so don't get rid of it lmao