Yeah, it's shit. Not gory (major points lost), and not even that scary. The Descent and even Frontiere(s) did a much better job of depicting blood-thirsty subterranean humanoids on a rampage.
Come on TDigs, are you hearing yourself? Who cares if it's not gory, anyone who judges a film by amount of bloodshed is being pretty foolish. Gore would be nice if this were meant as a brutal horror film, but it isn't. It's a suspense film through and through and a great one at that. I can't believe you didn't like it, the acting from the two main leads was tremendous. Shit how can you possibly love Funny Games but hate Ils?
Besides, Them isn't about subterranean humanoids on a rampage. At all. Are you sure you're thinking of the right film?