The Night Before reunites the filmmakers behind 2011’s great “cancer comedy”: 50/50. There’s Joesph Gordon-Levitt, again occupying the story’s lead role. There’s also Seth Rogen, again providing schluby support. Finally, there’s Jonathan Levine, again taking the director’s chair.

Missing is 50/50’s screenwriter Will Reiser, whose sensitive prose provided that film with the perfect balance of comedy and drama. The Night Before trades in Reiser’s singular vision for a virtual stable of writers: including director Levine, Kyle Hunter, Ariel Shaffir and frequent Rogen collaborator Evan Goldberg. The results are pretty much what you’d expect. While The Night Before’s log line and attached talent seems to hold great promise, its script is an unequivocal mess. While good-natured and occasionally fun, the film isn’t incredibly funny and is plagued by tonal inconsistencies. Yet, its most salient failing is the incredible narcissism of its central character, which hampers viewer investment.

The Night Before features an implausible setup. Due to the death of his parents in 2001, 30-something Ethan has spent the past 15 Christmases with life-long friends Isaac (Seth Rogen) and Chris (Anthony Mackie). As their 2015 Christmas celebration begins, it’s clear that things are changing fast for this triumvirate. Recently married Isaac is expecting a baby with his wife Betsy (Jillian Bell). Chris, who has become a famous football player, is conflicted over his progressive steroid use. Lastly, Ethan has become a struggling musician and is spiraling into a depression. This is due to his life’s generally pathetic circumstances, and an awareness that his group’s annual Christmas tradition may be permanently coming to an end.

This backstory effectively informs the film’s main arc, its wild hijinks feeling like the natural outgrowth of the characters’ preexisting individual tensions and anxieties. Isaac, for example, is secretly terrified by the prospect of becoming a father, despite having portrayed himself to Betsy as a pillar of strength and stability. This causes him to indulge in a plethora of drugs, and he spends much of the film in a blitzed-out fog. Gordon-Levitt’s Ethan has an arc that also feels consistent, a lucid progression of his pre-film history. It’s revealed early that the character is not simply contending with the potential loss of his Christmas traditions, but is also nursing the pain of his failed relationship with Lizzie Caplan’s Diana. This drives him to outlandish heights, such as his desperate ploy to reunite himself with Diana by engaging the help of Miley Cyrus, who cameos as herself.

Watching The Night Before, I found myself thinking about better movies that riff on similar subject matter – films like Francis Ha and Superbad. All three of these films tackle how the progression of time, and the natural changing of individual life circumstances, inevitably and often irrevocably alter friendships.

One way The Night Before differs from those earlier films is through its inconsistent tone. The story oscillates between the heightened realism found in other Rogen comedies, to flat-out fantasy, which is where the film is at its weakest. Part of this is due to certain story particulars being unbelievable, such as the trio’s obsessive pursuit of a fabled, invite-only Christmas Eve party called “The Nutcracker Ball.” Another is Ilana Glazer’s Rebecca: a crazy weed thief. Rebecca inexplicably poses as a rabid, hypersexual fan of Mackie’s football player character for the sole reason of stealing his bud.

Many of these bits have some redeeming qualities. Chris’s pursuit of Rebecca, for instance, involves her throwing down toy cars and making him fall flat on his back. Upon falling, he screams, “She ‘Home Aloned’ me!” which made me chuckle like a brain-dead cretin. Michael Shannon’s surreal cameo as Mr. Green (the trio’s weed dealer) is also uproarious. It’s odd tone also works better, as his interactions with the trio always involves at least one of them being under the influence.

Other bits of whimsy just don’t work. The pursuit of Rebecca features the trio commandeering a horse drawn carriage, which results in an accident where Rogen’s Isaac is dragged through the streets. Obviously intended to be an effective bit of physical humor, the sequence instead comes off as cartoonish and annoying. My eyes were rolling around so hard I felt dizzy. In fact, I was so annoyed that I started wanting to emulate the “Jeering Fan” from Happy Gilmore by screaming, “You suck, ya jackass!”

The performances in the film also vary, although no one is truly terrible. Mackie is playing essentially another variation on his Pain and Gain character: a dopey, good-natured buffoon who has unfortunately gotten addicted to juicing. Strangely, nothing about the character really registers, despite Mackie’s  preternatural strengths as a performer. This reflects something critical about the script, mainly that it is completely inept in creating strong character arcs.

Exponentially more successful is Rogen’s Isaac, whose unhinged intensity is one of the film’s most successfully comedic attributes. One potential negative is that his work doesn’t break any new ground for the actor. It strongly channels the same drug-loving, oafish energy that has been the actor’s proverbial bread and butter for years. Yet, Rogen’s performance also feels surprisingly deep, a tumultuous mixture of humor and rage. The apex comes through a drugged and drunken tirade that Isaac unwisely decides to record on his phone in the bathroom of a bar. This prolonged, tortuous monologue is classic Rogen, chalk full of his growly anger, anxiety and expletives.  The monologue circles around these emotions, directing them towards his wife and unborn child, and even calling the impending child a “cunt.”

It’s unfortunate that Rogen’s performance is not central to The Night Before. Instead, that role is occupied by Gordon-Levitt’s Ethan: an irritating, petulant bore of a man. Ethan is such a needy asshole that he spoils a lot of the fun The Night Before attempts to generate, and his gloom is never legitimized by the story. Unlike Superbad and Francis Ha, whose narcissistic characters were younger and more sharply defined (and thus more relatable and understandable), Ethan’s existential angst is never extrapolated on; it just sits there, and viewers are forced to wallow along with him. The Night Before never creates stakes for the character that feel involving or immediate, which turns him into a depressive Grinch. This further stymies the jovial, Yuletide milieu of an inconsistent film. The Night Before May genuinely want to entertain, but it only occasionally succeeds in doing so.