Back 4 Blood, released by the Left 4 Dead team, became one of last year’s most beloved co-op games. Developer Turtle Rock Studios wants to come up with a new additional package without losing the spotlight on the game. Olacka Tunnels of Terror, the game’s first additional pack, will be released on April 12.

Steve Goldstein, the studio’s boss, who announced that Back 4 Blood was hugely popular, said in a statement that the game had reached more than 10 million players. Expressing their satisfaction with the situation, the manager is confident that they will increase this number with a new additional package called Tunnels of Terror.

With the Tunnels of Terror pack, two new characters, Sharice and Heng, will be added to the game. In a new co-op mission called Ridden Hives, players will try to rid 7 different dungeons of zombies. In the additional package, we will also encounter new types of zombies called Warped Ridden.

The additional package will bring with it a free update. Thanks to this update, all players with the game will be able to experience the difficulty level no Hope.