Re: multiplayer/AI, consider a single player puzzle or challenge mode to grind through. Your game looks prime for generating tons of levels to unlock one-by-one.
Starting out with 0/low population with multiplayer-only is tough, chances are people coming on don't even have someone to invite, so they have to bounce.
Also as other says, working on your thumbnail, game page will help retain players. I also think personally working on getting the game working within itch.io and not linking off will help massively. I'm happy to help with the cookies there.
Viewing post in No-one cares about my game
Well yeah generating levels is fine, but the actual playing of the levels isn't really a single-player thing - I think there'd have to be an AI. Unless you can think of some variant game mode I could introduce where people could play single player. Capture all the hexes as fast as possible? I think that would be rather boring with no competition. :-)