This is a game developed by Beatriz Zallo Hernandez and Gorka Magra Tolosa for the Universidad Oberta de Catalunya (UOC). This game is a third person shooter coop, singleplayer and multiplayer zombie survival, It has not main story nor quests in it. It's meant to be a GTA alike game.
Download Link for Linux/Mac/Windows: https://www.dropbox.com/s/h01wdwqb4potoja/gzaDemo.rar?dl=0
Beatriz Zallo Hernandez
Gorka Magra Tolosa
Just extract the zip in a folder, open it and double-click on GZA.exe, it should open the typical unity window to start the game.
W,A,S,D: Move the player / The car you are controlling.
R: Reload your current weapon.
E: Ride a car (you should be near one, you can't steal police cars).