In Force Seven, the player is in charge of a specially trained squadron which consists of seven crew members, all with different expertise. Their task is to infiltrate the energy production plant on the planet KARIS by rescuing any survivors and destroying any aliens that are holding them captive.

The player is equipped with a flame thrower which they can use to destroy the aliens, but caution must be taken so that they do not destroy survivors by accident. If the player spends too much time in a room, a green alien appears in their exact location. It is invincible to shots, so the player needs to get away as soon as possible. If the player comes into contact with any aliens, their energy is depleted. When the player has no energy left, the crew member they are controlling dies, requiring them to select another member.

Also in each room are supplies, and the player can stock up on more ammo, grenades, or health if required. Teleports around the facility warp the player to a room with a blueprint reader. Using this lets players either travel between the plant's six floors or to another area within the same floor.