I.T. Kid

Before Heli Attack 2's weapon drops and Heli Attack 3's campaign, there was one clearing, one machine gun and one endless problem. Heli Attack is SquareCircleCo's 2001 original: hold your ground, destroy as many enemy helicopters as you can and chase the highest score. Move with the arrow keys, aim with the mouse and keep firing -- the loop the two sequels would build everything else around.