Vintage Story. It’s a very good survival, very customizable experience too.

I think it’s a game that shines best in a multiplayer civilization RP tbh but even as a single player game it’s a very nice survival. It may look similar to Minecraft at first but it is very very different and in all the good ways.

Plus mod support is so good, by design, even the website itself has 1-click installs.

Oh and it has chiseling.

Xcom 2: War of the chosen

Minecraft: Java Edition. You need internet the first time, but afterwards it’s fully playable offline and also has LAN support built in.

Barony mayb slay da spire 2

Factorio is great, how has no one mentioned it yet? Also Dwarf Fortress, Into the breach and “FTL - Faster Than Light”.

They all have native ports and are moddable.

Factorial and FTL even have huge overhaul mods, that change most stuff so they don’t really get boring.

Technically, Satisfactory (3D Factorio, but more chill) allows you to host your own servers. You can host a server in your LAN, connect to server via IP -> enter the server’s local IP.

There is also Terraria which is very low spec.

Caves of Qud. I’s like if Dwarf Fortress’ adventure mode was actually good, and set in hyper-post-apocalypse scifi world where the very water you need to drink (or if you’re amphibian, splash on your skin) is also the world’s currency

Farming Simulator (pick which year/edition), it’s surprisingly relaxing after whole day in office.

Satisfactory, building game, a bit heavier on resources since it’s 3d but it’s good

If you like 4x games, I would suggest X3:Terran Conflict/Albion Prelude from Egosoft. Its older, so wont be a burden,(CONTROVERSIAL OPINION ALERT) and probably the last good game from egosoft (/CONTROVERSIAL OPINION ALERT)

Space game set in a huge world with multiple factions and in a breathing world that can and does change with time with or without your actions… hundreds of hours of gameplay, with options for building your own empire… and its got a huge modding scene that can make it even more alive.

Once you start getting your personal economy going, you can take a more macro chill approach to the game, you can sit in a mothership issuing fleet commands and letting the AI handle everything, or you can get right into the cockpit of a corvette/fighter and dogfight yourself. While building massive station complexes to produce goods to sell and generate funds with… or to build your own ships and fleets with.

Endless Sky is a pretty cool open source space game.

Also Dwarf Fortress.

NetHack

Endless fun

Kenshi. Sandbox rpg, citybuilder and more. Pretty unique and unforgiving, but the replayability is endless if you are into that sort of thing (lots and lots of mods as well).

I’ve played Stellaris for years, although I am really not liking the direction Paradox is going with their AI, and it really puts me off of their games.

The Planet Crafter seems pretty neat, though I’ve only played the demo. It’s a first person survival crafting game where you terraform a planet.

Valheim has a local server you can set up that has it work offline. Shame it’s not on gog, but it’s on Humble which I don’t believe has online checks like Steam, but I had it working with steam offline mode.