Nice! I liked the whimsical art style, and the aiming controls presented a nice challenge. I wasn't clear about what the cats do, if anything.
I only made it to the second stage so far, but I'll try again later and see if I can complete the whole game.
Edit: Beat the game! 5159 enemies killed, 5216 sushi, no continues.
Also, I ran into a bug -- pressing the 'esc' key in the browser causes the game to freeze.