Use the mouse to move, press space to spin. This is how you'll attack. You can fire the green balls back at him - use this. Later, you'll need to spin to attack him when he launches himself at you, but wait until he stops glowing.
UPDATE: Made the game just a little bit more forgiving. BET YOU WEREN'T EXPECTING AN ACTUAL GAME, HUH?! Don't worry, I'm still making memes. They're coming. Anyway, had this lying around for a long time, brushed it up, and added that cool GFX I showed previously. Also credit to greenscreencat for the front-facing cat. Hope you like.
