I really liked this game.
The art was good and I liked the little details added like the devils nose animating when hes annoyed.
Music was ok but I think more focus should be put into finding some truly great tracks rather than ones that sound like 10 second loops, your gameplay is centered around music afterall!
Good execution on the theme and it's only the second rhyme style themed game I've seen so far so it was a welcome break.
I would have preferred to be able to use QWER as my keys so I could play with 1 hand but this may not fit your vision when it comes to handling difficulty.