异形症候群

Two players control two soldiers, named Ricky and Mary, who fight through large eight-way scrolling levels while rescuing their comrades that are being held by aliens. At the start of each level, a time bomb is set onboard the infested ship and the players must complete their task before it runs out which will result in the ship being destroyed. After they have rescued a certain number of hostages, the exit opens and they can pass through it in order to fight the end-of-level guardian . If the guardian is defeated before the time runs out, the players are then able to move onto the next stage. Once all seven levels are completed, the game starts over with more aggressive aliens, and less time on the clock.