Zombie Wars

Zombie Wars is the 1996 sequel to Alien Carnage. It picks up the story three years later as the aliens return to enslave the Earth. Halloween Harry and Diane, who has been promoted to field agent and is now also a playable character, have to save the world again. A number of other friendly characters have been added as NPCs.

There were plans to make a third game and a cartoon based off of that, but nothing came of it.