This reminds me of a game where you explore a sandbox world, in which most players choose to harvest and rearrange the blocks that make up the terrain in order to build whatever they decide they should build.

At night, monsters come out and attack you, so you should build a protective structure or have weapons and constant vigilance.

Specifically,

• It has a procedurally generated world.
• The player is the only intelligence.
• Things are pretty hard, and there's no leveling up to make it easier. It takes a while to physically reshape the world into what you want.
• Its super brutal. Like, an improperly controlled fire will burn down a forest, and probably kill you while you're trying to put it out. And there's lots of ways to kill yourself and generally ruin everything.

Its also a timesink that I wasted a week or two playing before quitting, so I'm ROT13ing its name. zvarpensg. In case you're interested. It's also behind a paywall and pretty buggy, so hopefully that will discourage long-term casual play.

EDIT: Its not particularly rational, but it does have a lot of the traits mentioned.