The plot involved an alien invasion of Earth by a reptilian race known as "The Visitors". In this game, you play as Mike Donovan, a resistance leader who enters the visitors' huge spaceship in order to blow up its reactor by setting explosives at key points.

The aliens will try to stop you as will surveillance, cleaner, maintenance, and security robots. If you touch any robots or are shot by them, a static charge will cause your hearbeat to increase. If this happens several times you have to rest or it could kill you. In 8 different laboratories you will find formulas for Red Dust which is lethal to the aliens - releasing it into air purification plants will kill many of them and also slow the robots. You can use a laser or when its charge runs out, you can jump over or roll under enemies.