Arrow keys to move player 2 (green) and WASD keys to move player 1 (blue). p to fire laser for player 2 and q for player 1. You each have 10 lives. Fight each other to the death!!!! It may lag if the players swap sides; it is supposed to work but it doesn't seem to work and you will be forced to refresh the game. If when you fire and it hits your opponent but doesn't change the health, I'm sorry It is lagging and I don't know what to do about it.
Thanks to @123768631 for the pen text engine.