I'll toss in my recommends:

Vintage Story is a standalone minecraft-like, which takes elements from Terrafirmacraft, recreates them in a custom engine and adds an apocalyptic time-travel twist to create a crunchy survival-crafter experience with a meaningful stone age, where pottery and whatever you scavenge from ruins remains important into the midgame because there are no rock or wood picks. Casting Copper to exit the stone age is mid-game. The Bronze Age is difficult to exit. Late game is Iron and wind power. Endgame is steel, alcohol, and cheese.

The recent 'Resonance Archive' update (v1.18.0) added a meaningful endgame site rich with doomed civilization lore. (Spoilers abound, obviously, but also a potential selling point. YMMV)

I have been getting good mileage out of Wildmender, which is the very finest voxel waterflow simulator you can drown all your plants inside. The devs are green party save-the-rainforest types, but if you care to hold your nose, there's a decent single player game with co-op privation modes available underneath.

My playgroup has been mucking around in Tribes of Midgard. For the 7 bucks I paid in I've gotten a good 30 hours of play in just the Saga Mode. The game really only feels viable when you hit the 3-5 player 'sweet spot' for a critical mass of gathering/exploration. It's a fairly generic collect-a-thon with cosmetics and a procedural map. Most of the unlocks for play related items are golden horn, but there's a platinum currency for whales to obsess over. Just click the black viking chick on the cosmetic menu's banner to buy some... (lol no)

The other game that perpetually draws my attention is CK III, (a not-really indie game) which I mod to scratch my particular autismal fixation on Vikings. I will never get tired of repeatedly sacking Rome and stealing the Pope's fancy hat.

I'll second Symphony of War as being worth the buy in. (Got my hour per dollar out of it. You probably will without even hitting the DLC.)

Necesse is a city builder with dungeon delving/island exploring mechanics I also got my hour per dollar out of. Early access, though.

ZERO Sievert is all the slavic post-apoc flavorland of Tarkov, but single player (ie no hackers) and top-down 2d. Another good buy for the hours per dollar, although there's a good chance of ongoing development nuking your save at some point further along in the Early Access process.