The first post-launch downloadable content for Portal 2 will be coming to all available platforms (PC, Mac OS, Xbox 360 and PlayStation 3) and will be completely free.
The DLC will include new test chambers for players, a challenge mode for single and multiplayer, and leaderboards, among other content, which Valve’s Doug Lombardi has hinted will be ”more videos or comics.”
A challenge mode would be perfect for Portal 2, which will definitely increase its replayability. Let us know what you think.