NZA is a better and more fun zombie s/h game than the L4D games- period. It has better visuals, atmosphere, setting, weapons, mechanics; enemies are smarter and there are more of them; the environment actually affects gameplay... even the lightning strikes before the thunder is heard!!
No way this is a 3.1 / 6.2 game. It's the most fun coöp TPS I've played since EDF2017.