This was downright vicious in two player mode. You could use your gun to gently knock the ball off target, or make it roll across the floor, when in your opponent's area to kill him. You could always make sure that both players passed each stage, or just try to sabotage each other's chances of beating the level :) You always played a stormtrooper guy unless you typed in the name of one of the computer players (like 'Squishy' to play the space-hopper-like alien).
My cousin and I picked this up in a food store (?) for 50p. We were going to use it as a blank disk, but once we played it, we were hooked. Basically, it was a cross between breakout, pinball and tennis. Your little guy used a 'gravity gun' which would pull the ball towards you. If the ball hit your guy instead of the gun, you die. Trust me, this game is classic in 2 player mode...