Not good. It took DC decades to get a non-Superman/non-Batman superhero onto the big screen and this was the best they could do? Green Lantern is dull, uneven, and unfocused.
There are a couple of good things. Skargard was a decent villain, it was cool to see the Lantern Corps, and the action at the end was pretty decent. But this movie was a waste and could barely qualify as 3D. Again, if you're doing to do a 3D film, then SHOOT THE DAMN MOVIE IN 3D!