The Talos Principle II

Worth noting that the beta patch branch, just got FSR3 with FrameGen recently. That might be extremely handy for playing on something like a Steamdeck. The game is slow enough, that the type of artifact's generally caused by FrameGen might be ok. Or at least acceptable on the steamdeck.
24 hrs to get to ONE ending. still "playing" 143.1 hours later.

Sounds like me. I got my first ending in about 40 hours. I wasn't really going out of my way to solve everything. After that ending, I went back to just before the final megastructure part and did the rest of the lost puzzles, which unlocked the12 golden gate puzzles. Those bastards were hard, but unlocked a better ending. Then I started a fresh playthrough, trying to solve everything. Still working on that. Had to consult walkthroughs on a couple of the Sphinx puzzles. Got about 100 hours in the game. Love it. Probably even more than the first one.

Both of these games, it's the way they're structured that leads to very lengthy play sessions. You finish a puzzle, think to yourself, "I'll do one more." That leads to more. Then you finish an area and think, "I want to see what the next area looks like." It's all little nice bite-sized chunks. Then 3 hours later, it occurs to you that you really have to pee.