There are a few of them. _Spy Party_ is a game in which one player is a sniper and the other player is a spy at a cocktail party pretending to be an NPC. In _

There are a few of them. _Spy Party_ is a game in which one player is a sniper and the other player is a spy at a cocktail party pretending to be an NPC. In _Who's Your Daddy_, one player is a father whose goal is child-proof their surroundings on the fly to thwart the other player, a suicidal baby. _Evolve_ was a game in which a team of four hunter players hunted a single monster player. _Natural Selection_ is close to what you describe; one player on each team is playing an RTS and their teammates are playing a FPS. One side is space marines, the other are aliens. Marines have guns, but aliens can move through vents, scuttle up walls, etc.