OK, I've said this before, and I will say it again. This game is very similar to Rebuild by Sarah Northman but you control all the aspects of combat, travel, resource management, trading and survival. Each character has personalty traits that can, and WILL, compliment or contradict each other. The world somewhat continues while you are "offline" so you could possibly come back to one of your best characters dead or missing or similar. It also can get annoying by possibly being far away from base camp, and get radioed that there's in-fighting and tensions are boiling over.
I only say all this because this really isn't like any other zombie game, with exception of Rebuild. There is actually a little more character development than Dead Island with certain skills, but at the same time each character isn't truly that important (so don't get attached).