I was expecting to be a minority voice, but it seems underwhelment is widespread. I wasn't bored by the film, but I think it is rivaled for plot-holes, inconsistencies and ridiculous behaviour by the characters only by Hitchock's Frenzy.
Something that no-one else seems to have mentioned - that Father-Son expedition to the waterfall: how long were they meant to be going for? Dad took a shitload of equipment, and the boy was freaked out at the prospect so I assumed it was for days, but they were able to get back to base almost immediately. And what was the purpose of the trip? To show him how they caught fish? Wouldn't both the kids already know that?
And the soundproofed basement where they moved after the baby had been born - why weren't they there all the time? And how did it flood?
Oh and that exposition white board apart from being silly was also misleading. It was written on there that were at least three creatures nearby, but the number of attacks, and the brief shot at the end of the creatures scuttling away from the sounds, suggest that there were many more.
And that ruddy nail! Why was it even there in the first place?