Basically it's a mouse driven strategy game, going from map to map. Your goal in this game is to get your base into a state where it can be declared a government with it's own constitution. And how you do this is explore (scout locations for goodies or important area's), expand (clear out area's of zombies, then use materials to wall that area to your fort, unto which these area's may be counted unto what your fort needs, like food from farms), exploit (scavenge area's full of food and goodies, or use certain plot of the fort you grabbed and gain resources from them) and exterminate (meet other factions in the area, form aliences or declair war).
The factions are all very interesting, they all have their own uniqueness about them. Some are almost like a poision to your people, others will change your group forever. The zombies are an obstacle mostly, a constant strain and the main problem in the game, there will be a few events with them but not much else. And surprisingly, there is a story here, you'll have to work with the factions of each map to find out what it is if that's what you want, otherwise you may skip it by just getting to the constitution as quick as you can.
I very much enjoy this game.