Controls:
keyboard: s/d to move, w/s to aim, q to jump/join game, e to shoot.
keyboard: j/l to move, i/k to aim, u to jump/join game, o to shoot.
gamepads: left stick horizontal to move, left stick vertical to aim, gamepad_x to jump/join game, gamepad_y to shoot.
gamepads: right stick horizontal to move, right stick horizontal to aim, gamepad_a to jump/join game, gamepad_b to shoot.

Start game with space/gamepad_start when everyone has joined!