The graphics are definitely crude, but I love the amount of content! I agree with the other people, the music is pretty good, but doesn't really fit. 

Well done! Catchy music, easily understandable gameplay and the bosses are really good.

Its a good game but i would have add an restart button if youre dead.

I like the music too, it isnt so much spooky, especially the happy boss theme, but I like it :)

Hey! I would love to provide feedback for the game if you can produce a Browser version of it!

Cool game! Smooth controls and minimalistic level design that still makes you understand where to go in what order! :) I appreciate there being many bosses (relative to the rest of the content).  Last boss was really cool and creepy. 

Though I liked the music somewhat it didn't quite feel so fitting all the time.

Good work!