As a landmark gaming franchise, the two Left 4 Dead games laid the groundwork for an entirely new subgenre of the co-op shooter. The defining traits of this subgenre involve hordes of weak enemies supported by a few unique special ones, all controlled by an AI director that manages pacing in real time. The AI director, a major selling point of Left 4 Dead, makes sure that players always feel challenged but never unfairly so.
Left 4 Dead has spawned plenty of imitators since its 2008 release, many of which became huge successes in their own right. Although there were rumors of a Left 4 Dead 3 for many years, it's recently been revealed that the project was cancelled in the early 2010s. Nevertheless, fans of the formula have got plenty to be excited about in 2021. There are several brand new titles on the way, including a spiritual successor developed by the original Left 4 Dead studio.
Back 4 Blood
Left 4 Dead first began development at Turtle Rock Studios in 2005, three years before the studio was acquired by Valve. It wasn't until 2010 that Turtle Rock became an independent company once again, although Valve retained the rights to the Left 4 Dead franchise.
Now, 11 years later, Turtle Rock is working to release Back 4 Blood, a spiritual successor to their original title. Back 4 Blood's gameplay will be largely identical to Left 4 Dead, with both 4 player co-op and 8 player versus modes. While there aren't many other details so far, we do know that Back 4 Blood will use a card-based buff system to allow players and the AI director to add modifiers to gameplay.
Warhammer 40,000: Darktide
Another new title in 2021 that follows in the footsteps of Left 4 Dead's classic formula is Warhammer 40,000: Darktide. Fatshark, the studio behind Darktide, are known for their Vermintide games, which feature 4 player co-op gameplay set in the Warhammer Fantasy universe. Conversely, Darktide is set in the sci-fi Warhammer 40k universe, with players taking on the role of a squad of Imperial Guardsmen investigating a Chaos Cult on the Atoma Prime planet.
With its futuristic setting, Darktide will have less of a melee focus than its fantasy predecessor. As such, fans of Left 4 Dead can expect a much more similar gameplay experience. This is particularly true as the Cult enemies appear to be worshippers of Nurgle, the Chaos God of disease, decay, and death. As well as disease-spewing daemons and corrupted space marines, Nurgle is known for creating hordes of undead plague zombies.
Aliens: Fireteam
The recently-announced Aliens: Fireteam bucks the trend of the 4 player co-op shooter subgenre by cutting a player out. Despite this, the upcoming title from new developer Cold Iron Studios seems well-suited for the subgenre. Set in the universe of the Alien movies, Aliens: Fireteam will have players take on the role of a group of marines sent in to contain a Xenomorph threat.
Enemies will range in size and power, from Facehuggers and Weyland-Yutani Synthetics, all the way up to the massive Praetorians. Players will pick a class of Marine, and be able to customize their weapons, gear, and perks, before taking on the alien menace.
Tom Clancy's Rainbow Six Quarantine
Tom Clancy's Rainbow Six Quarantine is an upcoming squad-based tactical shooter, and the fourteenth game in the Tom Clancy's Rainbow Six franchise. The game is inspired by the Outbreak event for Rainbow Six Siege, which challenged players to take on hordes of enemies infected by the Chimera virus.
Rainbow Six Quarantine will expand on the Outbreak game-mode, and players can expect to see more special infected as well as larger maps. One interesting detail that Ubisoft Montreal have revealed about the upcoming Rainbow Six title is that instead of a virus the driving force of the enemies in Quarantine will be a technological parasite. This gives the potential for interesting interaction with some of Rainbow Six's electronic and EMP-based gadgets.