Intruder!

Intruder! is a 1-player arcade game for the Atari 400/800.

Somewhere in the nation's capital lies a research and development installation powered by four small fusion power plants, which provide the energy for this facility. Two dedicated robo-units provide maintenance and security for this installation, and have been programmed to permanently eliminate any unlawful intruders to this level. These robots have functioned so efficiently that researchers have taken to storing all their classified documents on this level. Then, an earthquake struck, the filing cabinets have been strewn throughout the level, and the 4 power plants have begun to overheat. You control a small robot which must deactivate these 4 fusion reactors and neutralize the robots.

The player plays in a large screen full of filing cabinets with 4 red fusion reactors spaced on the screen. The player can push rows of filing cabinets to rearrange the environment. The goal is to avoid the enemy robots, and trap them within a block of filing cabinets so they cannot move. The player also has a limited time to access the 4 fusion reactors and deactivate them to prevent the facility from melting down. There are 4 difficulty levels, which affect robot speed, number of robots, and the time until the reactors melt down. The player is rewarded a score based upon the time they take to complete the mission.