Publisher Warner Bros. Interactive Entertainment and developer Turtle Rock Studios have announced Back 4 Blood tops 10 million players.

While Back 4 Blood tops 10 million players, the game broke 6 million total players not long after its launch in October 2021.

Furthermore, the companies also revealed the game’s first post-launch expansion, Tunnels of Terror, which is launching on April 12th across all supported platforms.

“To achieve such a milestone in the short time since the launch of Back 4 Blood is a historic event for our studio and this franchise,” said Turtle Rock Studios President and General Manager, Steve Goldstein. “As we look ahead, we’re excited to keep the momentum going with our upcoming expansion, Tunnels of Terror, which will offer more cooperative content for fans to continue cleansing the world of the Ridden.”

Here’s a rundown on the new expansion:

When Tunnels of Terror arrives on April 12, you can jump into an all-new co-op activity known as Ridden Hives, where you can explore seven different dungeons full of labyrinthine tunnels below the depths of Evansburgh that are infested with a new Ridden type, Warped Ridden. To claim exclusive loot and rewards only offered in Ridden Hives, players must outmaneuver and overcome the daunting new Warped Ridden, including the landmine-setting Urchins, monstrous Shredders, and damage-dealing Rippers. The new Warped Ridden variants are also playable in PvP Swarm mode.

The upcoming expansion introduces two new playable Cleaners – Sharice, an axe wielding firefighter, and Heng, a tough as nails, no-nonsense restaurateur.

Also included in Tunnels of Terror are eight exclusive character skins, seven new legendary weapons, 12 new weapon skins, new cards, and more. The expansion will coincide with the release of the No Hope difficulty setting, a free update adding an extra level of challenge for elite players.

Please note, all playable content included in the Tunnels of Terror expansion will be accessible by all players in a party as long as one player in that party has purchased the expansion.

Back 4 Blood is now available across Windows PC (via Steam), PlayStation 4, PlayStation 5, Xbox One, and Xbox Series X/S, as well as on Xbox Game Pass at launch.