Arrow keys to move. If you hear a beat sound, that means press the "Charge" button. Click or press the space bar to shoot a yellow bullet. Don't touch the pink bullet! If you do, it'll take some battery from you and have some of your score. If you die, it'll say how many points you and he got.
This is how it works = If you touch the pink bullet, you'll lose energy and the enemy will gain points. If you hear a beat sound, you lose a point. You can move in a direction forever.
