Quite an enjoyable game
The first time I played this I died immediately... But after a few more attempts, I got the hang of it and managed to rack up 42 coins after stomping on 20 enemies. I think you may need to either slow down the speed just a tad, or make the screen somewhat bigger so you can see what's ahead to plan out your jumps (usually jumping onto the head of an enemy can result in landing on a spiky one and you have no control over it). The music was good, and the sound effects were nicely done. So all in all, an enjoyable game, well done and keep up the good work.