A nice, classic beat-em-up. Feels very retro. Art, music, even the sound effects are seriously retro. I'd recommend enhancing that feel by using a CRT visual effect, so you really feel like you're playing on an old computer or arcade machine.
Felt odd to just be able to pick every upgrade, every time. Maybe give people a choice of major upgrades, like new attacks, faster movement, etc. Didn't find any other faults.