If Zombie Realism is what you feel has been lacking in the genre then you are going to want to get to know this game and it's developer
The Dead Linger is an FPS (first person shooter) zombie survival game made and published by Sandswept Studios. It features a world size world and randomly generated worlds that can spawn structures such as forests, cities ranging from big to small, mountains, caves, grasslands, and any other biome you would find in the World. Also, the game will support an old-game mechanic that allows the player to interact with objects and NPCs or other characters in the game. The game can (will) be buy-able in the Alpha, which will allow you to buy it at a discounted price of 25$ with no DRM. It will be buyable on the TDL site (Thedeadlinger.com) and will not use Steam. The game will utilize the Ogre 3D engine to render and simulate the game and due to its rendering methods, the game can be released on Linux and Mac alongside Windows PC. NOTE: Buying the Alpha helps with bug testing and funding the final game, along with early and cheaper access to the game.