Games made for the PlayStation Network (and the Xbox Live Arcade, and WiiWare) are supposed to be quick and easy, kind of like snacks you munch between bigger meals of Halo Burgers and Super Smash Potatoes, but something funny happened when Sony released PixelJunk Monsters, a tower defense game for the PlayStation 3. It became as big an obsession for some gamers as the latest Call of Duty or Grand Theft Auto. It was such a hit that Sony is releasing PixelJunk Monsters Encore, an expansion pack for the game, in late April -- though as we learned when we spoke to Senior Producer Deborah Mars and Associate Producer Matt Morton recently, it wasn't just obsessive fans that brought about Encore.