Alien Syndrome (1987)

The extra-terrestrials in this game are anything but friendly. They're slimy monsters that are holding space colonists captive aboard seven alien starships. This super action game challenges you to free the helpless hostages. Search each ship's deadly levels, using flamethrowers and laser cannons to vaporize alien scum. Look for maps to help you find your way. After you've saved all the captives from one ship, you must destroy its powerful leader before you can move on to the next ship. Remember, to the aliens, you're slime. And they want you good... and dead!