The story is about a 3 star (for horror), but the production effects are so great that I HAD to give this four stars.
This is a FUN creature feature with some wicked awesome monsters and an interesting protagonist who is not annoyingly cocky, but instead empathetically emotional. This is a fun get smashed Friday night movie for gore freaks, and it would scare the crap out of a kid or lightweight. I imagine if I saw this before I developed my scare immunities, I wouldn't sleep comfortably for a few days - that's how great the makeup is.
I'm a huge proponent of practical effects, which is probably why I like this movie so much. The first two acts are mostly exposition, and then the concluding twenty-five minutes is all monster fighting. During the fight, Jack does some foolish things like discard his weapons constantly, then when the next monster attacks him, has to struggle to find another makeshift weapon (and this gag is pulled at least three times). I thought compared to earlier outbursts, the actor didn't showcase Jack's rage when it came to fighting the monsters, and it's not just because the monsters dwarf his aggression with their growls. I think the actor was trying to inject some fear into Jack, but it just came off as Jack wasn't in his uncontrollable anger mode.
I'm definitely looking forward to the sequel and hope they don't lapse into using loads of CGI, as the practical makeup/fx was the meat of the movie. I like how bits of the creatures' anatomy mimics the aesthetic of plumbing and pipes, which is Jack's porfession (in particular, their blood looks like dirty pipe sludge).
Also worth mentioning is Robert Englund's performance. He does a great eccentric professor. Once his character is affected by the monster heart, his body language is just astounding as if I was watching a person actually possessed.