The cooperative mode is the true sequel to Dungeon Defenders. Expect more heroes, more towers and even more loot. New features like an expanded story and a 24-player overworld are also in the works.
Dungeon Defenders II is the sequel to the popular tower-defense role-playing game, Dungeon Defenders. Unlike it’s predecessor, Dungeon Defenders II features a cooperative and competitive mode. Heroes, cosmetic items, pets, and more will transfer across both modes.More Info @ PCGamingWiki