The new Survival mode takes place in the Glittering Caves of the White Mountains, and pits one to five players against a series of incoming enemy and boss waves, trying to keep towers up and stay alive as long as possible.
The "Goblin-town" map for the one-lane mode sets the battle in the Misty Mountains near the Witch-king's dwelling, as seen in The Hobbit last year. We've got videos of both the new mode and the new map down below.
To celebrate the release, Monolith devs are jumping in on the PlayStation Network and hosting a special "Play with Devs" session on Friday, March 1 from 5-8pm PT. The game is free this week for PS Plus members, so if that's you download away.
Monolith says the new content is coming "soon" to both PSN and XBLA, so no date yet. The company tells Joystiq that the new one-lane map will be free. Survival Mode will also be free for anyone with a season pass (included in the boxed retail copies of the game), but cost extra otherwise.