I agree with both RisanF and RoughNTumble. The game does have "cash in" written all over it, but it's also better than most movie tie-in games I've come across (which isn't saying much). It's your typical "show up, defeat a wave of enemies, level up, and get to the next platform" deal, however, I am really enjoying the way you can chain your constructs together to perform combos and attacks. The constructs themselves are pretty imaginative in their function throughout the game, and once you get them all, you can perform some pretty cool combos if you're fast enough.
I haven't beaten the game, but from what I can tell, the developers of the game TRIED to make a real Green Lantern experience for gamers, and got a lot of it right. With a better story, and some improved graphics, this could be a solid gaming experience for fans. Then again, it's not the worst tie-in you'll play, but it's also not the best superhero gaming experience you're going to come across.