It's no secret that Back 4 Blood is best enjoyed by playing with three friends. Its co-op-focused gameplay explores the formula created with Left 4 Dead with a modern spin, but not everyone playing games enjoys multiplayer experiences. Unfortunately, while the option to play solo exists, Back 4 Blood doesn't offer a whole lot for those looking to cleanse the world of Ridden on their own. Recently, the game was criticized for the way that it gates players using the "solo campaign" option from earning Supply Points, achievements/trophies, and unlocking new Cleaners to play as.