This is the worst movie I can ever remember seeing. Every character is annoyingly written. I actively hoped for the death of: two of the teenage boys, the hunter who had apparently never handled a firearm before, the shrill ex-wife, the newbie USGS employee that teetered and ditzied her way through this movie enough to ensure that the pretty female scientist trope is met, the first 2 guys that enter the underground part of the plant-filled with escaping gasses- without any breathing or safety equipment or even informing someone about what they were doing. The only character I cared about was the dog, and he should bite his handlers for putting him in this atrocity.
If the writers had been better this may have been a 4 to 5 scored comedy. All this without saying how truly awful the plot, special effects and editing is.
Avoid unless you are curious about just how bad a movie can be.