I’m exploring building a game around it (not in it) with Kikai, an unholy marriage between zachtronics games and starcraft, where units (and buildings) are uxn machines with devices to interact with the outside world. This allows you to fully customize the whole army and strategy to be whatever you like.
Buildings for example, take a bit of the role of linkers (or even compilers), they are just another Uxn machine with a Factory device. The most basic form of a building and the one that you will have by default is just a memcpy of bytes from a source ROM to bytes in the RAM of the newly created unit. But by investing a bit of time you could for example have pre-made behaviours that you can link on runtime based on that particular match needs. Units also have a radio and can send messages between them. WIth some more code you could have a handler that rewrites parts of the code broadcasted from a building allowing you to deliver OTA updates!
My objective for the game is that it works out of the box as a normal RTS but that once you get the gist of it you can start automating here and there so there is no high cost of entry but there is infinite extendibility.
There is another very interesting project in the same direction that Devine (the creator of Uxn, Varavara, Orca and Nebu, as well as many others) shared with me recently when I explained my project to him: Doldrusidus which is incredibly fascinating. It goes in the same vein, small ships in a multiplayer universe each of them running Uxn machines inside.
Kikai and devlogs: https://marcecoll.itch.io/kikai Doldrusidus: https://desertslug.itch.io/doldrusidus