I recently discovered Celeste and love it so far. It’s a skilled platformer that doesn’t seem as punishing (edit) compared to other platformers that I’ve played, but still challenging enough to be satisfying. (edit: And the base story difficulty is not as bad as some other platformer games). The story is also really nice (overcoming depression and mental health stuff), not something I usually play but I was really engaged with it, and communicated in a nice simple way (not a ton of cutscenes like story-heavy games). edit: Celeste is similar to Hollow Knight, though I got stuck at a part of Hollow Knight and haven’t picked it back up in a while. Celeste is much easier than N++ and Super Meat Boy, IMO.

(I had intended to play it on my 4k TV, but I found that it has a significant delay that makes it hard, and I somehow didn’t notice it in other games. It’s much easier to play on my PC).

Also RE the OP’s mention of simple phone games, I really like “Simon Tatham’s Puzzles”: iOS, Android on Google Play and F-Droid. It’s a collection of simple puzzle games that I enjoy idly playing for a few minutes at a time.

I’ve been interested in that! How do you like it compare to games like OpenTTD, Cities: Skylines, and Factorio (sort of)?

I love the trains in Factorio, and I enjoyed trying out OpenTTD for a bit, but I eventually got bored with it because airlines were easy money, and it was too easy to lose money when building a train network, and it took too long to expand. In Cities: Skylines I could never really figure out how to fix traffic, I felt like silly little things were causing it to back up. I don’t think I ever really got seriously into rail traffic in it, though.