Terraria
I feel like it's a really good option as a sandbox game, and one that people know well! You can build your own house and decorate it how you like (althoguh not with the freedom like Minecraft or Valheim) but people could post thier houses, or village set ups! Crafting areas, Boss arenas, all that good stuff! I saw someone else suggusted it as well, so I'm sorry for the repetitiveness. This is a super cool idea!
