"The Justice League" was apparently a tie-in with George Miller's now-defunct Justice League film. The game project continued for another two years before being shut down as well. Few details about the game itself are available, but the images show a variety of superhero locales (Gotham, Metropolis) and Gwyn describes it as a "third-person brawler." A proposed versus mode was also included which put together a quartet of half good guys / half bad guys into an arena for a street fight.
Despite the cancelation, Gwyn says that "the team was brought onto another superhero project" rather than being canned – that project appears to be the Green Lantern game from Double Helix that was released in June of last year. Additionally, despite project similarities, no assets from the Justice League project transferred to the Green Lantern one.
Gwyn is currently working at Rockstar San Diego as a senior artist on a "confidential AAA title." Unfortunately, between the time it took to write this piece and ping Mr. Gwyn, he's password protected the images. If you'd like to share any information or assets regarding the Justice League game, don't hesitate to get in contact with us.