A playable early Left 4 Dead prototype has appeared online

An early playable prototype for Valve‘s zombie shooter Left 4 Dead has appeared online.

Zombie City, which is a Counter-Strike: Source mod, is now playable, with dozens of videos of the mod appearing online.

The prototype is very rudimentary, featuring no zombies, instead, players face off against AI terrorists that can only attack the player using melee attacks.

The mod, which was made playable thanks to modder WolfCl0ck is the latest in a wider spread leak of Counter-Strike maps. As PC Gamer points out, Turtle Rock founder Michael Booth discussed the mod in the Left 4 Dead commentary track.

“While we were developing bots for Counter-Strike: Source we discovered that a few of us armed to the teeth with automatic weaponry against 30 knife-wielding enemy bots was a lot of fun. After shipping Counter-Strike: Source in late 2004 we started experimenting with new game prototypes. That basic kernel of ‘small team of friends against hordes of clawing enemies’ was something we kept coming back to and we soon realized that the ‘co-op vs the horde game’ had a ton of potential.”

Released in 2008, the original Left 4 Dead was developed by Turtle Rock Studios, which was known as Valve South at the time. Release on the Xbox 360 and PC, the game saw players progress through campaigns in groups of four, taking down hundreds of zombies.

Following strong reviews, a sequel, Left 4 Dead 2 was released in 2009. The series has been largely dormant since then.

The team behind the game, Turtle Rock Studios, would go on to develop Evolve, a multiplayer game in which four players played as hunters against one human-controlled monster. The game was met with disappointing reviews and player reception.

Turtle Rock’s latest game, Back for Blood, was released in 2021.

VGC’s review of the game, which saw the studio return to its Left 4 Dead roots, read “It seems backhanded to say that a game is only worth playing if you can find people to distract you from the actual game, but if your group wants something mindless to wind down after an intense night on Warzone or Rainbow Six: Siege, Back 4 Blood is ideal.”