But it is one of the minority of 3D movies that really makes excellent use of the 3D. There are no gimmicky things poking the audience in the eye or flying out of the screen, although there's one scene where it must have been tempting. (If you see the film, you'll know the scene I mean when you see it.)
Instead of relying on such cheap tricks, the director has used the 3D to give it real depth. At one point, as the characters make their first attempt to get out of the soon-to-be-flooded cave, the audience sees the action from behind a cascade of falling water. It would be a nice effect in 2D; in 3D I had an urge to put my umbrella up!
It also avoids the mistake Cameron made with Avatar: all that fast action-movie camera work (that, combined with the 3D, left me with a three-day migraine). Instead the camera work is used to draw the audience into the scenes: slow in the diving scenes, so you feel suspended in there with the divers. There are a couple of places where the camera angles are a bit self-consciously 3D - one where the audience's "eye" is right on the surface of the water as the characters surface, and another where you're looking down into a narrow shaft as the characters climb upward - but overall it's very well filmed. I didn't give a crap about the characters, but I had several moments when I really felt a part of what they were going through. That's the real potential of 3D, and the director deserves kudos for that.