SPOILERS, OF COURSE
I had a bit of a hard time with some of the absurdities. Curve the bullet, yeah right. BUT -- if you approach it as a fantasy, the movie works. As such, I was entertained by it.
Overall, it's a bit of an adolescent fantasy. Wimpy guy who suddenly finds out from an uber-hot chick that he's part of a fraternity of assassins and becomes a stud-muffin. What pimply 16 year old who's been picked on all through school wouldn't want to live out that dream?
I can't really rave about it because I did find the whole premise rather juvenile (I am 52 years old, after all), but I must admit, when Wesley smacked his supposed best friend in the chops with his ergonomic keyboard, I laughed my ass off.