Fortress II

The player controls a large immobile fortress in the center of the screen which can fire in the four cardinal directions. Alien vessels appear at the 4 sides of the fortress, and rapidly fire at the player. The player must quickly position their single large cannon and fire towards the enemy before their fortress is destroyed. The player loses a life with each hit, and with 3 lives lost, it's game over.

The game is not so much a sequel to the original Fortress as it is an updated version of the original game.