Zombie Panic! Source is a standalone cooperative, survival-horror, first-person-shooter! Set in the middle of a zombie apocalypse, players start as a small group of survivors attempting to stay alive. Each map will have its own objectives to complete and win the round or survive by a period of time.
ZPS v2.0 Release Date and Halloween Contest
Rely does show just how capable the Source engine STILL is after all these years! Absolutely breathtaking!
Easy on your system + amazing physics, graphical quality and engine flexibility and support is why Source is my favorite game engine.
And ZPS team makes some fantastic maps for damn sure. Valve quality type maps.