Robot Entertainment has just announced Orcs Must Die! 2 , sequel to the particular tower defense released in 2011 on Live Arcade. The main Feature of this new chapter will be co-op, whose absence was definitely felt in the first episode.  Orcs Must Die! 2 will offer a new campaign, new enemies, new system upgrades and will be presented for the first time during the upcoming PAX 2012. Video and pictures to follow.