I've never seen anything like a zombie role-playing game in the market. Excluding those Chinese web novels that have a system in a zombie apocalypse world. Like a really focused zombie only world, but the roles are represented through a standard class system. Obviously there will be changes to the classes name and skills, but the overall professions have the same branches as the fantasy professions, except it's modern with science fictional classes in the mix. Yeah, quite the game it would be. No demons, alien-like creatures are allowed, but the enemies should still be zombies. Damn! Now I have this small urge to create a system for a zombie apocalypse world. Hopefully it recedes with depression and shit.
http://www.edenstudios.net/allflesh.html more suggestions: https://www.reddit.com/r/rpg/comments/2z70ri/any_good_zombie_apocalypse_rpgs/
I am note quite sure of what you want but what about these? https://store.steampowered.com/tags/en/Zombies/ Dead Island: Riptide Dying Light Dead Rising
Here are the links: Dead State https://store.steampowered.com/app/239840/Dead_State_Reanimated/ Dead Age https://store.steampowered.com/app/363930/Dead_Age/
I would like a Zombie RPG with the combat/crafting/exploration of Dying Light and the management of resources of the base or family a la Dead State Reanimated or State of Decay, with the story being on the start of the infection and the player being the father of a family, surviving, changing bases, meeting other survivors and traveling until you find safe haven to survive the Z's. Then the game, will change the style of gameplay a la They are Billions or Rebuild Series games. That would be my dream Zombie game, though that will be a RPG only on the first part....