I’ve been meaning to do a puzzle game recommendation overview on kbin.social/m/PuzzleVideoGames after forgetting to back up an old post on the subject before purging my Reddit account, but I’ll share a few recommendations for the time being. Given that lots of Steam games are a much better deal if you wait for the Winter or Summer sales, I’ll list the regular and expected sale prices as such: (Regular/Sale). Since you’ve played the Portal Games and TSP, other three-dimensional exploration puzzle games in that vein include The Witness ($40/$10), The Talos Principle ($30/$4.50), Quern: Undying Thoughts ($25/$10), and Lightmatter ($20/$7). Among those, I think Quern is the best due to its resemblance to Myst without the solutions to most puzzles being overly obscure. Other three-dimensional puzzle games that focus less on exploration and more on puzzles include The Room Collection ($25/$7) and The House of Da Vinci Complete Bundle ($54/$27), with both series sold as individual games as well.

In terms of longevity, some 2D puzzle games have—in addition to their regular puzzle sets—daily puzzle sets or custom puzzle generation, adding to replay value at the cost of a degree of repetitiveness. These include LYNE ($3/$1.50) and LOOP: A Tranquil Puzzle Game ($5/$2.50), among others.