Highly Moddable Space Station Sim · By Vox Games, intenscia
Double Fine abandoned DF9 long ago, then released it as is, the game will never be finished.
Go look up headlines like "Spacebase DF-9 Development To Cease, Game To Release"
If someone else wants to make a game with the same sort of gameplay, you let them. Honestly the visuals aren't even the same.