Portal 2: Co-op demo impressions from PAX 2010

One of the longest lines at PAX 2010wasn't to play anything, but to see a live demo of Portal 2’s co-op mode. Valveonly showeda few of the mode’s puzzles, but we can say pretty assuredly that it’ll be another beloved addition to Portal's universe.You'll probably see fan-made plushies of the adorable co-op robots before the game even releases.

Valve’s decision to include co-op was based on feedback from the first game. As often happens with puzzle games, players sat together and helped each other unravel Portal’s elaborate puzzles, or passed controllers back and forth. Now they can work together in the game’s world, rather than outside of it. The new mode, of course, doesn't replace or interfere with the main campaign we already love. The in-game reasoning is as simple as it ought to be -GLaDOS needs to run some cooperative tests, and humans are incapable of cooperation, so: robots.

What we most wanted to see in the mode was character. A vanilla, “okay, fine, this is two player now” mode which lacked Valve’s sense of humor andcharacter design geniuswould have been merely passable. Valve, of course, delivers.

The two robot characters (“Orange” and “Blue”) are adorably in love, and remind us a little of Wall-E and Eve. GLaDOS is her typical sociopathic self, and passive-aggressively berates the players with comments like, “If this were a contest, Orange would be winning. It’s not though,” and “History will only remember one of you.” And it's not just to be cute - it's clear that Valve knows that all of this chatter generates camaraderie between the players, sucking them into Portal 2's world.

Upon beginning, the robotic duo is instructed to high-five each other to form a bond. That in-game interaction sweeps away any notion that these robots are mere avatars whose actions don’t affect each other. It forms a bond between the players and each other, and the players and their robotic bodies.The most endearing moment occurs when one of the players is destroyed -a replacement robot pops out, and its clueless cohort stops grieving and gives it a big, sincere hug, unaware that they’re both disposable.

So the Valve touch of awesomeis there, but what of the actual puzzles? Oh, the puzzles! Valve showed us a few basic maneuvers, like using both sets of portals to direct a "Thermal Discouragement Beam" through two walls to activate two receptors. Getting a bit more advanced, the duo directed a light bridgeover toxic goo, using both sets of portals to redirect it around corners without losing their footing. But the coolest thing we saw was the infinite fall maneuver.

Remember putting a portal above and below you in the first game? You fall forever and maybe puke (and an Achievement if you walk away for a while). Well, with two players, that motion-sickness distraction becomes a useful tool. One player sets up the fall with two portals, and the other enters the infinite loop. Then, when the falling player has built up some momentum, the originator of the portals can launch him out of an angled wall with a well-timed portal shot.

The maneuver is a clever use of two players, but we imagine its far from the cleverest thing Valve has designed. At the end of the co-op trailer we saw before the demo, GLaDOS mentions the team's "real purpose," which appears to bea terrifying gauntlet of death. We have a lot more to see.

Portal 2 is out February 9th, 2011, so you still have a while to wait, and Valve surely has more surprises.

Sep 5, 2010