The PopCap founders knew it was going to sell well - it was so polished and witty, such a basic joy just to watch in motion, that it could hardly fail - but in the months following its release, after it had been retitled Plants vs. In between rehearsals for a glitzy press launch involving gymnasts, light displays and a hulking mechanical prop that looked like Captain Nemo's steering wheel, I was shown a fleeting glimpse of a new game one of PopCap's many teams was working on, called, at the time, Lawn of the Dead. There was an unmistakable sense that the company knew what it was about, and, more importantly, knew who its audience was. PopCap was on top of its game, and about to release the long-awaited follow-up to its biggest hit. The last time I was here, immediately prior to the launch of Bejeweled Twist near the end of 2008, there was a certain air of confidence - politely understated, naturally - drifting through the corridors and cubicles. I've been pondering this matter ever since spending the day with PopCap, in the developer's Seattle-based HQ. Where do you start? How do you sift through the hundreds of different elements that made for a successful project, looking for the single magical idea that you should now be expanding upon for fun and profit? With failure, after all, there's no shortage of people offering to point out where you went wrong - "Your crafting system's wonky," "Lara keeps getting stuck on the scenery," "No, Denis, Cyber-Vikings aren't cool," - and then, of course, there's that little voice lurking in the back of your mind telling you that you saw all this coming in the first place, and just chose to ignore it. Learning from success - particularly slightly unexpected success - can be a lot more difficult.