Balancing. Finding the right starting % to “infect”, infection chances, and other small gameplay tweaks I’ll probably need to make before I can consider it “done”.
Scale. I’ll likely need to capture a good percentage of people on the AT protocol before it’s even remotely playable with a good chance you’ll interact with another player.
Content. This type of game requires new content all the time. For players it’s a passive game (sign up, join a cycle, forget about it), but the admin (me) needs to keep adding new variants, schedule new cycles, etc.