Fortress Underground

Fortress Underground for 8-bit Commodore systems follows the same general concept as versions on other platforms, but has a unique level design as well as its own spin on the gameplay.

The player controls a helicopter that must explore a cave system. The goal is to land on eight control points and then on the final goal point. Before starting, the difficulty can be set in eight levels and it can be adjusted how much gravity affects the helicopter.

Enemies and obstacles in the cave include flying satellites, homing bombs, timed laser barriers and different types of walls that can be destroyed or moved by shooting them. The helicopter constantly burns fuel which can be refilled by landing on a refueling point.

Upon losing a life, the game can be continued from the last control point. Completing the game relaunches it at a higher difficulty level.