I was halfway through explaining the concept of a Minetest game when I realized I can use Simutrans. hehe.
So, Minecraft is like Simutrans+pak64 rolled into one. You can get mods, but it's a complete game as-is.
Minetest comes with a default game that's like a very very very minimal pak - one truck, one train, etc etc. So you have to download games or subgames (both mean the same) from the forum. Best one that runs on my old computer is Carbone. There's some others that probably rock, but don't run on my old machine very well, so I don't know.
Right now, some of them generate odd terrain because there was a recent update to terrain generation (v7), but even using older (v6) for Lord of the Test game puts trees ~2-3 blocks underground, so it's more like bushes. Weird. But will probably eventually be fixed.
The community is small like ours, so sometimes progress is slow
