If you enjoyed The Witness, but kind of wish you could play a game that's filled with toilet humor, strong language, and general goofs, I have great news. That game both exists and is free: It's called The Looker. In the grand tradition of games making fun of other games, it's not the top, and it's not the bottom either: It sure is an entry.
I jest. I had fun, and you know what? It's free. It's a lot of effort for what amounts to a goofy joke about another game, and I think it's worth giving creator Subcreation Studio some respect for that. 97% positive reviews can't be wrong.
Here's how The Looker describes itself: "The Looker is a single-player game that respects you as an intelligent player, and it treats your time as... reasonably valuable (I mean, don't let me pull you off solving the Riemann hypothesis or anything). As such, I will level with you here—not every joke will be a hit, but there is no filler material, the puzzles are fun, and, if you really think about it, aren't the real solutions the, uhh... friends we make along the way?"
You can find The Looker for free on Steam.