Amazing. Totally over the top, ridiculous, full of plot holes that didn't make sense, cheesy as hell, and still takes itself seriously enough to not be an outright comedy. Whoever mentioned Army of Darkness was on the rgiht track, this really is just a braindead romp that you can enjoy the hell out of if you're not overly serious about telling a story in a film. There are snakes on a plane, the film lives up to it's title, and is bloody hilarious.
And again, I saw it with a bunch of college students, and naturally, when Jackson began the line "Now I have had it, with these mothersmurfing snakes..." everyone was saying it along with. Pure braindead bliss. 10/10