 The player now has more control over where they go, and finding one's way through the massive Fortresses is one of the major challenges of the game.The player must navigate through the maze, fight off enemy robots, security devices, and spacemen with their beam weapon, locate and destroy the central core of the Fortress, and find their ship to escape.The last is perhaps the most difficult part, since the Fortress explodes shortly after the core is destroyed and the player only has a short window of time in which to escape, with the exit never situated in the same place as where the player entered the maze.