They Are Billions

One great feature is that there’s a “roam” command for your units, that allows them to hunt zombies without micromanagement.
I don’t enjoy the fact that there are no saves in this game, as the missions get very long very quickly, and it’s easy to loose an hour or two of progress, because the last wave of zombies spawned where you didn’t expect it to. Same goes for not having the ability to speed up the game. I had to wait for 20 minutes for the last wave. Of course there are tons of fans telling people that if they need to speed up, “they’re playing it wrong”. I’d tell that those people need to get a life.