Witness-like puzzle game where you wander around an island solving wordlessly tutorialized puzzle panels using environmental clues and the game's language of symbols. (Between this and Understand, I feel like "Witnesslike" is approaching Zachlike levels of relevance as a puzzle game subgenre.) However, rather than drawing lines, Taiji's puzzles are based around turning on and off individual grid squares (although in some cases you do this by walking across a grid built into the floor, which does actually force you to trace a single line).
I had never even heard of this game before my twin brother suggested it (we usually like to get each other games or find a game to play together on our birthday, and this one just so happened to come out exactly on our birthday), but I had a blast playing it alongside him, taking turns at the reins. There's just something very satisfying to me about figuring out and internalizing all the different rules, and having a partner to bounce ideas off of and get a different perspective from went a long way in getting us through all of the puzzles.