The art is good, and the gameplay concept is pretty good if a bit repetitive, but one problem is the fact that it's impossible to kill anything without getting hit because of how small your attack range is. The pillow is the only useful upgrade, partly because of the aforementioned problem. But the shop is random and you can't leave the shop unless you choose something, even if you choose something you can't afford which is weird.
With some adjustment and balancing this should probably be pretty good.