From the back cover:
"Nine teenagers enter an abandoned cemetery to celebrate their high school graduation. Before the night is over, most of them will die."
Joyride is the book equivalent of a slasher flick. Its fast-moving, well-written scenes are cinematic, visually splashy in a gory and non-gory way; many of the characters are unlikeable and lack nuance (it's clear who the reader is meant to root for and who deserves reader hisses); and it has all the spooky atmosphere, gratuitous sex and blunt violence one would expect from an unhinged-killer-on-the-loose work.
One thing that really made me enjoy this novel was that its killer - Robert Atchinson, a.k.a. Cleats - wasn't always a murderous psycho, as shown in Joyride's flashback chapters: Atchinson is a fully realized person, with a (semi-)relatable motive for slaughtering these largely obnoxious and stupid adolescents.
I enjoyed this a lot. I'd recommend it to those who enjoy gory slasher films. If you don't like cinematic/written fare like this, avoid Joyride.
(Big thanks to TreSart L. Sioux for turning me on to this book!) =)