Valve has been teasing the DLC's new game modes for weeks, and as announced on the official Left 4 Dead blog, they include a co-op challenge mode, and the previously mentioned Mutations. From Valve:
These week-long runs of new gameplay modes range from "Realism Versus" mode to "Chainsaw Massacre," which gives all players chainsaws with an unlimited supply of gasoline. There are over 20 Mutations planned, each playable on all L4D2 Campaigns. Mutations are exclusively available to owners of "The Passing" DLC.
In celebration of The Passing, Valve employees are logging on for some multiplayer madness on Left 4 Dead 2 tomorrow. Devs will be online on the PC from 11am to 5pm PDT and on Xbox Live from 7pm to 11pm PDT. To play with one of the game's creators, friend any one of the following:
On PC:
L4D2_DEV_1, L4D2_DEV_2, L4D2_DEV_3, L4D2_DEV_4, L4D2_DEV_5, L4D2_DEV_6, L4D2_DEV_7, L4D2_DEV8, L4D2_DEV_9, L4D2_DEV_10
On the Xbox 360:
L4D2 DEV 1, L4D2 DEV 2, L4D2 DEV 3, L4D2 DEV 4, L4D2 DEV 5, L4D2 DEV 6, L4D2 DEV 7, L4D2 DEV 8, L4D2 DEV 9, L4D2 DEV 10
Sharkey says: Valve has really stepped up with The Passing after disappointing owners of the original Left 4 Dead who were expecting a ton of DLC before a sequel. Can't wait to team up with a dev for some good ol' fashioned zombie hunting.
