TwoThree
Very simple arcade. You point the gun to numbers falling from the sky, and shoot numbers two or three from your gun. If you shoot 2 with 2, it explodes. If you shoot 3 with 2, the one remains and falls to the ground spelling doom, because you don't have anything to shoot ones! I especially dislike 17. Have you tried to shoot down 17 with 2 and 3? I have.
I can see how this skill can be useful in real life. All you need is a real life number gun and numbers falling from skies.