Oolite is inspired by the 8-bit classic Elite, and many aspects of gameplay will be familiar to players of that game. In the tradition of open-world games, there's no overall story: you can be a millionaire trader, a veteran combateer, a feared pirate, a lonely miner, a notorious smuggler, or all of them, or something else entirely, based on your own actions.
bobeff
commented
3 years ago
Oolite game and source code are freely available under the GNU General Public License.
http://www.oolite.org/
https://github.com/OoliteProject/oolite
Other potential ideas can be found at https://forum.openmw.org/viewtopic.php?p=57882#p57882 and https://osgameclones.com/.