Nice art. Not only does it look good, but also fits the type of game.
I had couple of technical difficulties:
- couldn't press space at the beginning, as space was moving the browser window down, instead of providing input to the game. As a walkaround I clicked collapse button at the top, then expand. After that the game was receiving input as expected
- couldn't get past the first 3 enemies. First it seemed like the special move got stuck in infinite loop. Then even though the life of my opponents was 0, they didn't die

I found it to be quite hard. Maybe it's because I can't kill some opponents, like turtles or destroy rat nests.

I was also a bit lost with the control scheme. What I mean is I expected WASD to be relative to the direction my player was facing.