(Stinkalistic's description with a few minor tweaks) Arrow keys or WASD to move and space to shoot a Bullet and click 1 or 2 to change your weapon from a two tap Pistol and a 1 shot Shotgun. This is a cloud game so you are supposed to wait until someone is online and shoot Bullets at them, but be careful because you might be hit with an enemy Bullet.
@Stinkalistic Helped me to understand the coding a lot better.