The last game I did 100% was Psychonauts 2. I loved the world and after playing the fantastic story it was a good reason to spend some extra hours revisiting the levels.
No. The only screenshots in my steam library are of some glitches I took screenshots of because it looked funny. And at some point I had a script running in Counterstrike that took screenshots of the game results.
My theory is that it already has been released on Steam years ago, but not as a Valve title. It has sold millions of copies in a Humble Bundle, but nobody has ever played it.
It’s not really an adventure in the classical genre definition, but maybe Return of the Obra Dinn is something for you if you like solving puzzles and fancy murder mysteries.