A huge hit in England last spring and a shoe-in for instant cult-classic status, "Shaun of the Dead" is a hysterical dual-genre spoof about a 29-year-old London layabout who sees a zombie outbreak as his big chance to win back his peeved, reliability-seeking girlfriend by coming to her rescue -- a plan he manages to screw up in every conceivable way.

Writers Edgar Wright (who directs) and Simon Pegg (who plays the title character) have labeled their flick a "zom-rom-com" (zombie romantic comedy), and they delight in taking wickedly funny potshots at all the clichés that inspired them, beginning with the morning Shaun wakes up oblivious to a world full of flesh-starved ghouls.

Having managing to channel-surf past all the previous night's news reports of spreading undead hysteria (of course), he drags himself to a convenience store and back, in his own half-dead morning stupor, completely failing to notice his entire neighborhood is overrun with walking corpses. Eventually he catches on and sets out, with a cricket bat and his couch-potato roommate (amusingly slovenly Nick Frost), to round up his mum and his ex (Kate Ashfield) so they can fortify themselves inside -- where else? -- his favorite pub.

It's a terrible strategy (especially since he drags the chagrined girl and some friends out of a virtually impregnable high-rise apartment), but that's part of the joke. In fact, one of the movie's more round-about laughs comes as Shaun and his quickly-diminishing party continue to cross paths with a friend who is faring much better at leading her own group of survivors to safety.

An enjoyably low-budget endeavor given a sense of mock-slickness through zippy zooms and artsy editing, "Shawn of the Dead" is packed to the rafters with hilarious homages (George Romero and Sam Raimi films, a mocking reference to last year's "28 Days Later," goofs on John Woo movies, "Star Wars," "A Clockwork Orange" and more). But Wright and Pegg also get surprising mileage out of cheap, well-delivered one-liners ("Next time I see him, he's dead!") and slack-jawed double-takes from its gifted comedic stars -- many of whom honed their chemistry together on the hit Brit sci-fi satire "Spaced."

When scores of zombies inevitably encroach on the barricaded booze house, the movie's humor dips markedly as the bloody body-count rises, which is the one shortcoming that can't be easily shrugged off as part of the flick's cut-rate charm. But all will be forgiven with the ironic finale and an imaginative tongue-in-cheek epilogue that accompanies the closing credits.

In the days before quick turn-around from theatrical release to home video, "Shaun of the Dead" would surely become a staple of the midnight-movie circuit. But insomniac screenings or no, this movie is a guaranteed gut-buster for anyone even vaguely familiar with the fundamentals of zombiedom.