I really liked it! Very challenging when a lot of enemies start popping up. It has a lot of juice for a pixel game!
My biggest gripe, I think the "SPIN" at the end of a wave should look more like a button. I was stuck for a bit trying to figure out what to do! (maybe wire up an input button to spin?)
I'd kind of prefer SPACE to roll, but that's really a nitpick more than anything.
With it being just on a single plane, its kinda tough to dodge multiple enemies - maybe add a purchasable that increases number of dodge rolls or duration?
Other than that, good job!