Valve has released the first weekly "mutation" for Left 4 Dead 2's The Passing DLC, adding a new time-limited gameplay mode to the game.
"Bleed Out" mode starts Campaign mode players off with slowly deteriorating health that will eventually take them down. The mode also removes any health packs, forcing players to rely on pills and adrenaline for a temporary boost.
Valve has promised "over 20" mutations will eventually be released on a weekly schedule.
Check out our review of Left 4 Dead 2: The Passing elsewhere on Eurogamer.