On the surface, “Run Fatboy Run” promises hilarious satire of the sports underdog genre (i.e…. On the surface, “Run Fatboy Run” promises hilarious satire of the sports underdog genre (i.e. “Rocky”) in the vein of Simon Pegg’s other masterful parodies, “Shaun of the Dead” and “Hot Fuzz.” However, the film falls far short of the quality of Pegg’s previous efforts, completely unable to decide whether it’s parodying a genre or merely exemplifying it.

“Fatboy” revolves around Dennis (Pegg), an unabashed loser who literally runs away from the wedding ceremony with his pregnant fiancee,

Libby (Thandie Newton). Flash-forward five years to the present, where Dennis manages a strong relationship with his son Jake (Matthew Fenton) but still pines for an unavailable Libby, who is dating high-powered financier Whit (Hank Azaria).

Whit is successful, responsible and athletic – essentially Dennis’ polar opposite. Dennis becomes increasingly jealous as Whit’s relationship with Libby becomes more serious, to the point where he decides to run a marathon with Whit in order to show that he, too, is good enough for her.

The biggest issue with “Fatboy”, and what makes its satirical effort so unsuccessful, is the characters. Dennis is little more than a bumbling idiot, making every mistake he possibly can and acting completely unapologetic about it – at least at first.

This would fit in with the idea of parodying figures like Rocky Balboa if Dennis wasn’t so incredibly bland and uninteresting. His desperation to get Libby back and his attempts to compete with Whit come off as pathetic rather than endearing, and his failures are predictable rather than amusing.

Similarly, Libby’s enduring love for Dennis in spite of his actions and Whit’s affections is difficult to believe, and Whit’s extreme abrasiveness lying just beneath his appealing veneer is absolutely absurd. Rather than being sharply drawn to effectuate a satirical objective, the characters are blatantly stereotypical and generic.

The film’s plot also provides few opportunities for satire. This is where “Fatboy” seems to become confused about whether it is parodying the sports underdog movie or it is just a mediocre entry into that genre.

Dennis’ marathon mission follows an immensely predictable path – disbelief, inspiration, the “Rocky”-style training montage, and the renewed disbelief the night before. The film’s plot simply doesn’t differentiate itself enough from that which it is attempting to parody. As such, “Fatboy” leans far too much on screwball comedy, the height of which exists in Dennis’ overweight landlord following him around in a canary yellow scooter and spanking him with a spatula.

The comedy almost universally falls flat on its face, although one scene in Libby’s bakery offers relief in a few genuine laughs.

The one dimension in which “Fatboy” does succeed is, oddly enough, in empathizing with Dennis’ plight. While Dennis is nearly unbearable in the comedic scenes, whenever the film eschews the slapstick and slows down long enough to have a conversation between Dennis and Libby, the films asserts a surprising emotional strength.

The marathon itself adds to this, particularly one pseudo-surrealistic scene where Dennis hits the mythical “runner’s wall.” This empathy aspect is something that existed in “Shaun” and “Fuzz” as well – when the satire falls away, there’s still a significant and powerful investment in the characters that gives the film a poignant subtlety.

“Fatboy” manages this as well, despite the insanity of the satire and the blandness of the characters, attesting to Pegg’s impressive ability to play the role of the loveable loser. It is what salvages the film from being complete trash, although it’s not quite enough to elevate it from the realm of forgettability.

The problems with “Fatboy” are those of writing and directing, and they seem to originate from the replacement of Edgar Wright – the director and co-writer of “Shaun” and “Fuzz” – with David Schwimmer (yes, David Schwimmer, of “Friends”) as director, and comedian Michael Ian Black as a co-writer (with Pegg).

While neither does a particularly poor job, they are unable to emulate the wit and poignancy of Wright’s films. “Fatboy” ultimately succumbs to disproportionate expectations regarding Pegg, and this time around he’s without the skillful behind-the-scenes support present in “Shaun” and “Fuzz.”