Some single player videogames are more fun when played together

If you look online, it's easy to find recommendations for good multiplayer / co-operative videogames. My girlfriend and I have especially enjoyed playing games like Portal 2, It Takes Two, Rayman Legends, Overcooked and the Trine series. What we've found however, is that there are a bunch of games we enjoy playing together that are not multiplayer games at all! Because of this, these single player…