Robot Entertainment announced that the sequel to their 2011 action/tower defense hit Orcs Must Die is not only in the works, but should be released some time this summer, according to their website.

Orcs Must Die 2 will expand on the core gameplay established by the original, while adding more traps and enemy-types. In the first game, players control a "war mage" who has to prevent waves of raging orcs from getting from getting to a magical gate at the end of each level. Players use both the tactical placement of traps and direct combat to make sure no orc gets by.

The addition of co-op is by far the sequel's biggest change. OMD2 adds a second character, the Sorceress, adding new tactical options when playing as a team. While the War Mage might want to tangle with orcs up close, the Sorceress prefers to use "mind control and magic" to bring down enemies.

Orcs Must Die 2 will also feature a larger upgrade system, which will allow players to buy persistent improvements for all of their traps. Players will be able to grind by replaying any level, picking up more skulls (the game's currency), and buying improvements.

Players who purchased the original OMD on PC will get a "special bonus" in OMD 2.

Orcs Must Die 2 will be available on PC via Steam this summer. If you're at PAX East this weekend, you'll be able to give the game a test drive at the Robot Entertainment booth.