Not a bad start, also this is NOT a rhythm game. This would fit more as a platformer.
There is no music or sound effects so nothing to comment on there.
The gameplay is a bit off or hard at times. Should make a note in the comments that you jump by pressing the Z key. However, the last two levels are just out of nowhere and a sudden jump in difficulty (no pun intended.) You have wind blowing you super fast for the next to last level. Then in the last level (space level which I assume is the last level), there is no way to reset if you mess up. It sends you flying all the way back down to the bottom of the screen with no way to restart other than restarting the whole game itself.
There is only one sprite and it seems to be a sprite of Sonic from the Game Gear game series. Even when he jumps or dies, there is nothing that changes with his sprite. Should work on that if you end up improving on this game in the future. I also noticed in the Orange level, the one roof platform is probably one block size too low since I died trying to jump just underneath it several times.
Overall, seems like you were just testing yourself to see if you can make a decent game. It is not a bad start but I feel there is room for improvement, should look up some platform game design tutorials to help out.