Cinemania has my reviews of Iron Doors and The Hunt.
They're both kinda average, though for my money The Hunt is slightly better. What's interesting to me is where they fall down - in both cases it's a mishandling of a central mystery.
It's an oft-repeated semi-truism that the stuff you make up in your own head is cooler, sexier, funnier or scarier than whatever an artist can depict. This is how H.P. Lovecraft's stuff works (his horrors are typically more suggested than described) why you hardly see any footage of the Alien in the first movie, and why the Goon Show is better than Monty Python.
Where this falls down, however, is when the mystery is more interesting by far than the actual content of your film. The plot of The Hunt presumes the existence of an organisation that exists to run human-hunting games for the rich. From the implications in the course of the movie, we see that this society is ancient and secretive, as well as highly ritualistic. Unfortunately, we never get more than implications - instead we watch a gutter journalist struggle through the forest while masked men shoot arrows at him.
In Iron Doors the central question is who decided to spend a vast amount of money turning a series of bank vaults into a hybrid of Cube and one of the more irritating point-and-click adventure games of the 1990s. There's a vague implication that it's perhaps to do with aliens or something, but that's pretty unsatisfying when the movie opens up the possibility that alien-abduction-by-Fear-Factor-style-gross-out-challenge is actually a thing that happens to people. Why? What purpose do the aliens fulfill by locking an oddly-accented* German banker in a vault until he finally has sex with a random African woman**? I mean, if that plan solves a problem then the problem must be pretty bloody interesting - more interesting by far than watching a guy agonise about drinking piss and eating maggots.
I did an improv workshop once as part of a conference I was at, and the presenters talked at length about "opening the door, and then going through it" - by which they meant having the courage to follow your ideas to their logical conclusions, even if those conclusions take you in strange directions.
Go watch The Cabin In The Woods (assuming you haven't already) for an example of how to do this right. No seriously, go watch it. It will improve every single bad horror movie you have ever watched or will ever watch by its simple existence. Do it.
EDITED TO ADD:
Film Crit Hulk has a great essay on the "convoluted blockbuster" over at Badass Digest which is relevant here - especially the bit about judging whether revealing stuff is more worthwhile than concealing it at any given time.
*Seriously, the box says he's German and the movie is German - but he starts out sounding American then swings between generically-European and Irish for the rest of the film.
** The woman is pretty problematic in and of herself. The fact that she seems to be introduced into the maze for the benefit of the German banker is pretty gross, and I found myself really pissed off by the fact that she got subtitles when she was by herself, but not when she talked to the man.