Marauder

You've landed on an alien planet and penetrated the enemy base defended by armed attack robots. Your mission is to find your way to the heart of the base and to destroy the power center of the enemy's weapon system.

You start on the right side of a room, randomly selected. You must make your way though various rooms, killing or avoiding the four robots as you go. You need to find the power center and shoot it to clear that level. You must do this before the timer at the bottom runs out. Once you shoot the power center, you will get the remaining time as bonus. You are then sent to a new room to start again but now there are five robots per room. Get the power center again and there will be six per room. Get the power center again and you return to four robots per room but faster. In some rooms, you will randomly find a magic armor that will make you invulnerable for a short time.

The Apple II / Atari 8-Bit version add a second phase to the gameplay.