I don't see minecraft mentioned here often, but sweet jesus the mods that have come out of that game are mindbendingly cool. You can spend weeks strip mining r

I don't see minecraft mentioned here often, but sweet jesus the mods that have come out of that game are mindbendingly cool. You can spend weeks strip mining randomly generated alternate universes and pumping their oceans of lava/oil through liquid tesseracts to power your base while you gather enough uranium and other resources to eventually put together a full scale nuclear reactor. There are fully featured computers in the game with embedded lua interpreters and wireless networking so you can do stuff like build distributed power station monitoring software. There are also programmable drones called turtles, that can even be built to be self replicating. There are blocks that mimic quantum properties that you can even use to do quantum teleportation between multiple servers.