Your artwork kicks ten kinds of ass, trying the game out now
It didn't really get hard until level 4, then it got pretty hard pretty fast. Well, that is to say I didn't die until I got to level 4 and then I started dying A LOT
I think this game would benefit a lot from WASD controls too, arrows and mouse just feels awkward to me. Perhaps you could offer both control schemes?
Anyway good job so far!