In a nut-shell....
This bad:Splice is one of those rare contemporary horror films that is not based solely around the oh-no-it's-a-scary-surprise formula. There are no haunted houses. There are only haunted people. There is a monster but she is not a demon from the world of the Dark Ages. She has at least one three-toed foot in 2010. Yet Dren (the chimera at the heart of Splice) also speaks to something more primitive and universal than any spirit or phantom. Bioengineering could bring us a frightening world where monsters are real or it could take us into the golden age of humanity where pestilence and famine are endangered species. Splice is a little more coy about that question than most mad science movies. I would argue that the real act of bioengineering criticized by the film is the world's oldest: parenthood. This is where the film subverts a primal urge and takes movie goers to places that are uncomfortable. Serious questions about the roles of family are raised and elements of developmental psychology are dissected without slowing down the monster thriller at the film's core. Essentially Splice never forgets that it is a horror film with a ridiculous monster but it chooses to go for disturbing otherness than the "jump-out." To break it down even simpler: Splice is about something.
The inexplicable hit Paranormal Activity brought a lot of attention to itself and the horror genre. Some of it deservedly so. Most of it not. It's tricks are somewhat amusing. The film's homemade quality a welcome change from two hundred million dollar tent pole movies. It's attempts to make candles and Ouija boards and wires spooky are toothless but refreshing after a decade of CGI ectoplasm. My real issue with PA is that it's about being scared and nothing more. No characters to speak of really. No plot to speak of really. Nothing to say except "boo!"
I also have an issue with PA's monster: the demonic force tormenting the painfully uninteresting heroine. I do not find demons frightening or disturbing. Same with ghosts. I don't think about them. They're myths--relics from a time when we didn't know any better. I appreciate the craft of something like The Haunting or the religious force of The Omen or The Exorcist but they are about issues that just do not apply to the world of 2010. Ghosts aren't real and demons aren't either. Not that Miss Dren is any more realistic than a demon or ghost. The difference is that genetic engineering does in fact exist. Parenting brings with it many moral dilemmas. Splice is fantastic and unrealistic but its problems represent our world. It's the real world in an unreal movie. One day I might have to struggle with the ethical implications of a new being's moral education. I will never, however, have to worry about summoning an oogly boogly with a board game.
Splice not only demonstrates that horror does not have to be concerned solely with scariness but it also demonstrates that it can also be a good movie. The grainy night vision of Paranormal Activity is a good gimmick but aesthetically lacking. Splice is expertly filmed with atmosphere and movement. Director Natali creates compositions that rank among the most memorable in modern horror. PA's characters were non-entities performed by believable if not exactly engaging actors. Splice features three wonderful central performances. Sarah Polley is now one of the great movie mad scientists. Delphine Chanéac delivers the greatest mute monster performance since Boris Karloff.
Splice is not a perfect movie buy any stretch (for a review that gets it right read Annalee Newitz's review on io9) but it does demonstrate something often woefully ignored. Horror movies do not have to be empty. They can be about more than being afraid of the dark. Their goals can be loftier than scaring the bejesus out of an audience. They can have those goals without forgetting that people paid money to be creeped out. If you want creative, intelligent horror movies go see Splice. If you want to see some tired meaningless nonsense about the devil wait for the Eli Roth produced The Last Exorcism. If you want quality, then watch Adrien Brody do weird things with a bald, dinosaur-legged Frenchwoman.