This is the best suggestion so far. Outer Wilds is really nice game and fits well for the purpose asked by OP.
Other games i can see working well:
-Portal 2
-Subnautica
-DavetheDiver
-Stardew Valley
-Valheim (more fun coop though)
-Satisfactory
If you want to try to play together again Stardew Valley and Portal 2 are also solid coop choices.
It takes two is also fun with a partner