Arrow keys/WASD to move, but you can only move one direction at a time, but you can click space or Z to change your direction movement (e.g. you can only move left/right, until you click space, then you can move up/down). X key or click to attack enemies in the opaque box that you are standing on (it will be highlighted) Try to get the highest score you can!
Made in about 3-5 hours in a 48-hour competition for the first round of the GA olympics - speedcoding. :D Thanks to @robodog81 for help with one bug Post your best score in the comments!