Good thread. I've written an entire txt file of games I'd recommend, so I'm just going to dump them all one by one.
[1] Before We Leave
Cute little city builder game taking inspiration from the likes of Anno. I was very skeptical of it at first because it reeked of indie shovelware like those dozens of Mars/Moon colonization games, but it's actually pretty fun. Not particularly challenging but it's unique in several ways. The most notable thing about it for me was the fact that so much of the game centers around efficient space management - there is just not enough room for everything you'd want, so as the game progresses and the production pipelines get longer you'll end up naturally specializing islands and even entire planets just to produce one specific type of end good.
https://store.steampowered.com/app/1073910/Before_We_Leave/