The game reminds me a lot of Pizza Tower and Celeste with how speed combos and the artstyle. It was lovely, I think with more polish it could definitely shine :)

I can see it having potential, but the movement is really slow, and it can't be fullscreenned. I'm not sure if the other people are serious about it being fast, but if so, then I think you might have forgotten to implement delta or whatever they call it in GameMaker. With that being said, the animation of the main character is REALLY good, and I would definately play it again if these issues were fixed.

Bomby the Bomb is my favourite Sonic character

Once you learn the levels it can be quite fun to speedrun trough them.  Also I love the design of the main character and the final boss. (Though, I am confused wether or not you can beat it or if it's just an interactive cutscene.) 
The biggest issue is the way wall jumping works. For a short period after pressing the jump button you should not be allowed to cling onto walls. Also jumping off the ground while standing next to wall should not make you wall jump.

The only bug I encountered was a softlock in the second level. Jumping to the right off the tiny platform seen in the image gets you stuck.

This was pretty fun! A few fixes on the movement to make it more responsive would be awesome. I found the wall jump a little finicky and if you are trying to jump while on the ground but near a wall you'll do a wall jump.

Also found the cheat button lol "Sonic Got Through" and 50k points....beat that!

Well made game! I just wish that the movement wasn't as slippery.