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 games are often not mentioned in online 'best co-operative games' lists, and they won't be found when using the 'Local Co-Op' tag on Steam.
We first realized this in 2015 with Sam Barlow's Her Story. This is a narrative mystery game where you're exploring fragmented police interview footage of a woman whose husband went missing. The short video fragments can only be found by typing in a word that was said in that video. Even though I was the only one typing on the keyboard, it was fun discussing and solving the game together. We really enjoyed this game, and his third game IMMORTALITY is even better.
Later we played Return of The Obra Dinn, a great puzzle game where you're piecing together what happened to the crew of an East India Company ship. For each dead crew member you have to figure out three things: Who are they? How did they die? Who (or what...) was responsible? This involves paying attention to small details, and going back and forth through the various death scenes. Having a second person to discuss the game with, who also remembers things that happened in previous scenes, is really helpful.
We've also done quite a few real life escape rooms together, so we really enjoyed the puzzle game Lorelei and The Laser Eyes, which we felt features a lot of escape room-esque puzzles. The game recommends taking notes, and that's definitely needed! So when one person was controlling the game, the other would be in charge of the note taking.
For these kind of mystery / puzzle / narrative games it doesn't really matter that the game can only be controlled by one person at a time. We would often pass the controller back and forth while playing. Having two pairs of eyes also meant we were less likely to get stuck on tricky puzzles for long, and we only had to look up the solution online on rare occasions. I think finishing Lorelei on my own would've been significantly more time consuming and less enjoyable!
So I highly recommend trying this with a partner, family member or friend. If you're on PC then Steam also has the Remote Play feature, which allows two people to play together remotely, including the control handover. I haven't tried it myself but it should work well in theory!
Here are some recommendations for single player games to play together, aside from the ones already mentioned.
And there are a few we still want to try ourselves:
We've also played and (mostly) enjoyed Blue Prince, I want to share my thoughts on that game in a separate post soon!
If you have any other recommendations I'd love to hear, feel free to e-mail me!