I’ve been spending the past few months working on a top-down zombie survival co-op game, it’s still very much still in the workshed.
This game, whilst rather rudimentary in it’s presentation, is actually designed to be a realistic zombie apocalypse survival simulator. We used a team of zombie survival experts* to plan situations that would call for coordination, teamwork and an assortment of firearms and melee weapons.
* they watched Dawn of the Dead once or twice. We did try and use somebody who’d watched Resident Evil 2, but he was past saving.