Guiding Light is a co-op game in which you and a friend need to rescue stranded aliens from all kinds of sticky situations. One player is an alien who goes down to the planet to execute the rescue operation, while the other pilots the UFO to help guide the alien on the ground.
Astrumis - Survive Together is an exclusively co-op horror game. One player controls a survivor on an abandoned spaceship and the other the ship itself. They must work together to survive against the mysterious monster.