It's not the worst, as group-of-dudes comedy sequels go. We're not talking Ghostbusters II here. But of course, we weren't talking Ghostbusters to begin with. We were talking The Hangover. So this is a little weird: It's like expecting more and less at the same time.

The trouble starts early with that "based on characters created by" credit. What, so Jon Lucas and Scott Moore, the writers of the original, were too good for this? Possibly, yes. Even viewers whom that first film repulsed probably will prefer it to this torpid follow-up.

Anyway, where writing is concerned (it seems unconcerned), director Todd Phillips does the dishonors himself, along with Scot Armstrong, who co-wrote Old School with him, and Craig Mazin, who, uh, was one of eight writers on Scary Movie 3 and one of nine on Scary Movie 4. It's hard to discern each man's contributions here, but there is a depressing sense of mutual devaluation.

But where were we? Oh, yes, Bangkok with Bradley Cooper, Zach Galifianakis and Ed Helms—once again up to their blackout-inducing bachelor-party antics and ex post facto deductions thereof—along with Ken Jeong, Mike Tyson, that other guy from the first one (Justin Bartha), a drug-running monkey, a lost little brother and Paul Giamatti.

We're here because Helms' outwardly docile character has found himself a Thai fiancée (Jamie Chung), whose father (Nirut Sirichanya) compares him to bland rice porridge. So his arc will consist of proving himself not easily digestible after all. Loyally, Cooper's hardy partyer and Galifianakis' manic man-boy will assist.

The men lumber through their paces for a while, then compensate for the resulting stupor with little fits of overacted hysteria. It all just sort of drags. Yes, the antics are "outrageous." A clerical effort has been made to restage plot points from the earlier film, but rather than match its predecessor's unexpected delights, The Hangover Part II manages mostly unremitting disappointments. Where before there was debauchery, now we have, what, rebauchery? It would be ridiculous to speak of innocence lost, so let's call it innocence calloused by excess abrasiveness, grating motions too often experienced.

As gags flop and various surly phobias bloom into knee-jerk hatefulness, we're left to consider that the most inherently amusing thing about this film might be that its cast vetoed a Mel Gibson cameo. Probably the greatest vulgarity on display—aside from one ill-advised spoof of a certain Pulitzer Prize-winning photograph in the obligatory closing-credits slide show—is the sense that a comedy about the depravation of entitlement should seem to so resent the chore of collecting its inevitably huge box-office take.

Cynical isn't quite the right word. This doesn't seem like a movie that had empathy once, but got hurt. That might better describe its audience. But at least the film does, with its queasy, regret-inducing ache, actually feel like a hangover.