Though made in parallel with The Descent rather than as a rip-off of the superior film, this cavers-trapped-with-monsters effort still manages to be derivative, as undigested lumps of Pitch Black and The Relic bob around in the stew.
The monster/action bits are too jerkily-shot to be exciting and character business is 100% cardboard, with contrived rivalries and conflicts within the whittled-down expedition and speech balloon dialogue. It has one good underground climbing scene, but mostly serves as a counter-example by demonstrating all the ways The Descent intelligently diverged from the standard horror boilerplate.