There's a good start here, though I noticed a few issues. The attack has a timer on it that keeps you from attacking again, but there's no visual indicator, so it feels a little bugged. It's also difficult to control the direction of attacks, or at least it appears that way. There are segments of the levels with no variation, so when you walk through them (as you must do to clear all enemies) it ends up looking like you're not going anywhere. Maybe a few tiles or small ornamental details in the levels here and there just so there's always something showing movement. I like the sound design on the upgrade interface - you can tell you spent a lot of time on that. Overall, good effort!