Slither is a zombie horror film set in a dead end town somewhere in the South of America, where everyone speaks in that Southern accent, and everyone except for the main characters in the film, is somewhat on the ugly side. On the pretty male side, you have Nathan Fillion, last seen as Mal in Serenity, and essentially playing a Mal who uses fuck and shit instead of a Chinese equivalent that can't be blocked out by the censors. What that means is that we see Fillion as
"What will happen when I jump off this building, Answer Girl?"
"The zombies will not follow you, Pardy, and you still will not get laid."
I am being somewhat unfair to the film with that, because for all that the characterisation is very little, and the plot of the film nothing at all (an alien lands on earth, impregnates townsperson, means to devour them all), and the film skirts having any real subtext, it bubbles along quite nicely. It's funny, with a few good thrills, and a couple of nice scenes that'll stick with you after the film, mostly to do with slugs, but one of a foot turning off a tap. Likewise, Fillion, for all that this role demands absolutely nothing out of him for it, handles himself quite well in the film, and assuming he doesn't kill his career stone cold dead with White Noise 2, I kind of hope that we will be able to see him in more films. But still, for all that, the film knows that it's a b-grade zombie film, and it's not afraid to make the jokes, and have a good time with its premise, and that rubs off on you in the audience.
Essentially, Slither is a fun little b-grade zombie alien film and there's not much to say about that except that fact. It's fun to kill a couple of hours with.