Great game!
I think this is a great game. I've always wanted to make one of these but I don't have enough time in my life. Congratulations.
But I would like to point out a glitch for you, if you haven't noticed. The Level 2, Act 2 stage (Ice Land) I couldn't get past, Sonic wouldn't go into the tubes, or grind properly. So I thought I'll just restart, and then 2 sonics came on screen, he wouldn't run up slopes or collect rings.
Quite glitchy.
I can accept a few glitches.
Well done on this fine piece of work.