Steam page: http://store.steampowered.com/app/238430/
Early Beta In-Game Trailer: https://www.youtube.com/watch?v=rCVzN3AptWo
Cinematic Release Trailer: https://www.youtube.com/watch?v=uoMUhHLzoIk
The game modes that seem interesting are Escape and Extraction. In the former you complete objectives on your way to escaping, while in the latter you must fortify a location to stay alive until extraction is ready, and then guide the non-player survivors to safety. There's no real campaign, but the maps seem to be of a decent size, and with elements of randomization and co-op it could be decent.
They're calling it the spiritual successor of the "Zombie Panic: Source!" mod for Half-Life 2. The PC version is out and the Mac version is still in development.
