Sabotage

Sabotage is a 1981 computer game for the Apple II family of computers, written by Mark Allen and published by On-Line Systems. The player controls a gun turret at the bottom of the screen by either keyboard, paddle control, or a single axis of a joystick. The turret can swivel to cover a large area of the screen, but cannot move from its base. Helicopters fly across the screen at varying heights, progressively lower over time, dropping paratroopers. Waves consist of helicopters coming at progressively lower altitudes, a brief rest, then a wave of jets. The player earns points by shooting helicopters (5 points), paratroopers (2 points), jets (5 points), and bombs (25 points). Firing a shell costs the player one point, so if one is playing for score, there is an incentive to conserve ammo. The score never drops below zero. The game ends when the player's turret is hit by a bomb, when a single paratrooper lands directly on the turret base, when three paratroopers safely land atop each other immediately adjacent to the turret base (allowing the third to jump onto the base), or when four paratroopers safely land on either the left or right of the turret (that is four on one side, not four total). If four land on a side, they are able to build a human pyramid and climb up to the turret and blow it up once the sky is clear.