Don't know if this counts but Conan Exiles is a great game with a lot of content even if you are playing solo. Like...seriously...it could even be without survival aspects and it would be great.
I'm surprised that nobody said "Oxygen Not Included" you got to manage to produce even the oxygen. "Factorio" might be survival in a way. "This war of mine" is reaally good, can be really challenging "Mr Prepper" is good for some hours "Banished" is a little more city building but there's some survival onto it