I think alongside HUC is much easier, so many parts are already in place.

The game will be at first very simple: 2 factions (zombies and zombie hunter), the latter must make a kill every X blocks to not starve, the former is defenseless but has no needs. Both can take gems if they find them (they will all be dumb like Doom monsters)

And...send coins to yourself, and the conjured monster appears on map like magic, without a (live) hunter (exact amount determines what kind, spawnpoint, and behavior tweaks)

I hope this can be up and working in a month, and then regularly updating it and making it more complex will be fun. Running alongside Huntercoin makes this less difficult, only players need to update. (and they can't be forced to because there is no cost to run a Huntercoin add-on like this)