The game will feature gameplay similar to its predecessor, Lego Batman: The Videogame, but allowing players to play as classic Batman characters and other various DC Comics superheroes, such as Green Lantern, Superman and Wonder Woman Using this feature, the plot evolves around the Caped Crusader teaming up with the Justice League as they go on an adventure to defeat The Joker and Lex Luthor.
Source: Wikipedia, "Lego Batman 2: DC Superheroes", available under the CC-BY-SA License.
From the back of the box:
The Dynamic Duo teams up with legendary DC Super Heroes to save Gotham City!
Explore LEGO® Gotham CIty - the biggest ever LEGO® game environment!
Play as Heroes and Villains including Superman, Green Lantern, Lex Luthor and more.
Minifigures talk for the first time ever.
Master brand new Super Hero abilities such as Flight, Heat Vision, Freeze breath and more!