Kidnapped Champions. The second big mistake we made was pulling the ARG champions away from their communities too early. Based on contributions in various games, on the fan wiki and in the IRC channels, we hand-selected a few individuals who had contributed disproportionately to the ARG and offered to fly them to Valve.
In order to give sufficient time to notify them and make travel arrangements, Valve contacted them a few days before the start of the crescendo. We didn't require them to sign any NDAs, but to maintain the fiction, we encouraged them to take a step back from the ARG and claim that they had been kidnapped by minions of GLaDOS.
We failed to realize just how influential these few individuals had been in keeping the ARG running like clockwork. The wiki stopped getting updated, leaving other players confused as to what was going on.
In retrospect, a few minor changes may have prevented this. For instance, we could have altered the fiction of the story in a way that allowed the champions to keep rallying the ARG community in the anticipation that the kidnapping would come later.
The Crescendo. By far the biggest mistake of the ARG was the decision to move up the timeline for the crescendo. We originally scheduled this to start 24 to 36 hours before the imminent 7 am Tuesday launch, but we worried that this would give ARG players in other time zones very little time to participate. So we decided to set the completion threshold much higher so that the crescendo could stretch over multiple days. We moved the start to Friday morning to make it easier for international media to pick up the story before the weekend.
So what really happened? When the final ARG puzzle was solved, it pointed to a webpage with a count-down timer. Players immediately assumed that this was the count-down for the early release of Portal 2 -- a suspicion that they believe was validated by a clue that was sent to several media outlets that included the hint "4/19/2011_7AM=4/15/2011_9AM," where the first time was the published Tuesday release date. In retrospect, it wasn't very hard to see why the the community was surprised and disappointed when the timer reached zero only to be replaced by a page with another timer.
If our goal was to get media attention, then we got it. The extended crescendo gave plenty of time for the news to cover the event, but we sacrificed a lot of goodwill with the players. Those who had been participating in the ARG since the beginning felt let down because there were no puzzles left to solve. They participated in the crescendo by playing the games but found it to be anticlimactic.
