I'm going to guess that the game is a follow-up story to the movie, which is also coming out next Summer, since the Manhunters have nothing to do with Parallax (the movie villain).
The game will be published by Warner Bros Interactive, which might actually be good and will reportedly feature light constructs, flying through space, and taking down intergalactic criminals. Sounds sufficiently Green Lantern-y to me. Please be decent... I'm a big Lantern fan.
Green Lantern: Rise of the Manhunters is coming next Summer for all major consoles