Paul Aufiero (Patton Oswalt) works the night shift in an underground Staten Island parking lot. He mans the booth and the electronic arm that lets drivers in and out. He's 35 and lives at home with his mother. He has one buddy. And he doesn't have a girlfriend.

Total loser, right?

Well, not exactly. In Robert Siegel's odd and darkly humorous Big Fan, Paul does have a passion - for the New York Giants. Along with his goofball pal, Sal (Kevin Corrigan), Paul ardently follows the season, trekking to the Meadowlands on Sundays to take their prized seats: in the stadium parking lot.

A total football nerd who calls in to 760 The Zone, the sports-radio station, and offers his ranting post-game critiques, Paul seems strangely content with his life - a fact that his mother (an unmercifully nagging Marcia Jean Kurtz) and his successful lawyer brother (Gino Cafarelli) can't understand. And when Paul has an ill-fated encounter with the Giants' star player, linebacker Quantrell Bishop (Jonathan Hamm), this self-described "world's biggest New York Giants fan" faces a dilemma that goes to the very core of his being.

Written and directed by Siegel - who scripted The Wrestler, another keenly observed portrait of an outcast sports figure - Big Fan shares a nutty kinship with the obsessive-loner pictures of Martin Scorsese, namely Taxi Driver and The King of Comedy. And while Oswalt is no De Niro, the stand-up comic brings a schlumpy pathos to his portrait that shows depth and dimension. Scribbling the notes for his late-night call-in show commentary, Oswalt's Paul has a focus and zeal that have to be admired. When his mother - on the other side of the paper-thin walls - tells him to shut up and go to bed, Paul's indignity only makes his cause seem more noble, more urgent.

Siegel, in his debut as director, shot the low-budget Big Fan on a digital camera and achieves an appropriately grimy, gritty look. He has an eye for the telling detail and for the comedy in tragedy.

As Big Fan heads toward its stormy conclusion - and to Philadelphia, for a face-off between Paul and his contentious counterpart, a diehard Eagles fan - the question of loyalty looms large. Not just loyalty to a sports franchise, and to its players and coaches, stats and strategies, but loyalty to oneself, one's ideals, and one's dreams.

Even if those dreams don't amount to much.EndText

Contact movie critic Steven Rea at 215-854-5629 or srea@phillynews.com. Read his blog, "On Movies Online," at http://www.philly.com/philly/blogs/