A game doesn't have to having a scoring system or a quest tracker to have goals, and the ability to make your own goals doesn't preclude that the game has clear built-in ones, clearly indicating that it is a game.
Minecraft, DF, and Rimworld are all survival games, at least initially for the casual player. Whether it's explicitly stated or not, that's the inherent objective you get the first time you play - try not to die. "Don't die" is perhaps the most fundamental and instinctual game goal there can be. They're also all great sandbox games - tons of tools, tons of freedom, lots of emergent gameplay. Minecraft in particular really works well as both a sandbox game and as just a sandbox, no question about it. People turn on creative/god mode (essentially turning off the 'game' part) and go crazy just making amazing stuff.
Factorio has those things that are coming to eat you, right? That seems like a basic "survive" goal. Another great sandbox game from what I've seen... I've barely played it.
The Sims has you working with a budget right out of the gate, that's just a civilized version of "don't die." I'd say it's more simulation game (hence the name) than sandbox, you're pretty limited on what you can do/buy/build, but I'm sure there's at least some emergent gameplay that has occured in those games over the years.
Animal Crossing and Second Life are more like The Sims I'd think, I haven't played either at all. I'm not sure I ever played SimEarth, I can't really comment on it.
Gary's Mod, as I referenced in an earlier post, is explicitly just a sandbox and not a typical game.