Just a quick attempt at a quick game. Arrow keys to move, space or click to shoot a bullet, avoid space rocks and bullets from the enemy ship. (Enemy ship appears after score is greater than 11). Shoot at the space rocks and the enemy ship. For now, you can't damage the enemy ship; only your score will increase. Note, if you are too close to the explosion of a space rock, you will lose a life.
@griffpatch for the number counter tutorial.