Good way to pass a lot of time pretty quickly. Got to the last weapon (the laser) used it on a few levels, then changed to something else, the laser disappeared and never came back. The ways you can kill your character, or the enemies, don't seem to be the same all the time. Knocking the thing your from under you doesn't always hurt you. Sometimes knocking an enemy of the screen doesn't kill them, meaning you have to start over, because even if you have ammo left you can't see them.