You'd think you'd know what you're in for when the credits sequence traces the reproductive journey of killer-doll sperm. Still, though self-referential to the point of inanity, the fifth Child's Play film reveals a genuine braininess behind gory effects that are more silly than scary. In a conceit worthy of Charlie Kaufman okay, maybe Donald Kaufman Bride of Chucky's Jennifer Tilly, now playing herself, gamely delivers lines like ''I'm an Oscar nominee, for chrissakes, now I'm f---ing a puppet'' and dishes about Bound costar Gina Gershon. Cinehipsters will no doubt appreciate that Chucky makes air quotes and that his gender-confused spawn resembles art-rock diva Laurie Anderson. EXTRAS Those interested in a movie called Seed of Chucky will be satisfied with no less than the unrated um, ''fully extended'' version. There's the usual array of goodies (storyboards, a ''slashed'' scene, featurettes), but the highlight witty commentary by Tilly and writer-director Don Mancini references tasty deleted sequences not included here (what gives?). During a TV clip from the mun2 channel, an interviewer asks Tilly, ''It's more comedy than humor now, right?'' That's certainly an intriguing way to put it.