It's being written entirely in Python: Kivy for the desktop and mobile game UI, and aiohttp for the server.
I've written very detailed specification documents for every technical and game-design aspect of the game, and I've implemented the core game engine myself. I'm letting an agent do the rest, incrementally and under supervision, tweaking the specs as we go along. So far, a very pleasant experience.
My goal is to reach beta by the end of the year, and publish the game on Steam by mid-2027.