This is completely awesome, dude!! I've been making and playing Sonic fangames since 2001 and I've never seen anything like this..
Hope it ends up becoming a full game!
edit : also, I hope you don't mind me asking, but how did you keep the animations so fluid? Using bones?
And how did you do that effect, when he gets the power-up?
I guess I'm newer to construct than you, hahaha