If a comedy troupe like Broken Lizard or The Whitest Kids U Know had made Lars and the Real Girl, it might have turned out like Happy Birthday Harris Malden, a sweet, funny, and very odd comedy about growing up and accepting reality. It's the work of a Philadelphia filmmaking quintet called Sweaty Robot, and the opening credits are no more specific than that: "Written and directed by Sweaty Robot." I like that. The film is about friendship, and it was made by a group of friends.

Granted, making a movie with a bunch of your friends isn't always a good idea -- Adam Sandler, I'm looking at you -- but Harris Malden benefits from Sweaty Robot's familiarity and camaraderie. While it has some jokes that probably only the guys themselves think are funny, the film is so good-natured and charming, almost innocent, that even when I wasn't laughing I was content. It's a movie that wants to be your pal, and hey, doggone it, what's not to like?

Harris Malden (Nick Gregorio) is a 25-year-old Philly man who cannot grow facial hair. This is the consequence of a childhood tragedy that also had more devastating effects, but to block them out of his mind, Harris uses a black marker to draw a thick mustache on his upper lip every morning. Sometimes he changes things up by drawing a goatee instead. He has been using fake facial hair ever since the incident; the weird part is that no one says anything about it. Not his brother Nelson (Juan Cardarelli), whom he lives with, and not his best friend Paul (Eric Levy), who lives next door. Not the kindly butcher down the street or the middle-aged couple on his block. There is an unspoken agreement among all the people who know and love Harris that they will indulge him in this. They won't force him to deal with his tragedies until he is ready.

There's also an agreement, albeit a spoken one, not to let Harris leave the neighborhood by himself. He's a bit touched in the head -- not dumb, not mentally handicapped, just ... whimsical. He wants to be an architect at Paul's company, so he shows up at the office one day with a resume. "I wrote it myself," he says. "In cursive." Sure enough, he did. (Somehow, Harris actually is an architect of some skill, and he's an apprentice for another draftsman, played by Matt Walsh. The movie does not explain how this arrangement works, or how Harris became an architect.)

The conflict arises when a new person is introduced into Harris' sunny little world. She is Susan (Brigitte Hagerman), Paul's girlfriend and coworker, and it is she who addresses the elephant in the room when she finally meets Harris. Now, suddenly, everyone has to face facts. Have they been wrong to let the mustache charade go on this long? After all, they only did it out of love. Were they so concerned about Harris' psychological well-being that they stifled his growth?

Yes, that is the major problem faced by the characters in Happy Birthday Harris Malden: They fear they might have loved Harris too much. How can you not like a film with a crisis as humane and lovely as that? The story's emphasis is on laughs, most of them gentle, many of them surreal (including an out-of-nowhere subplot in which Nelson becomes a model thanks to his magnificent mane of hair), but there's always that underlying niceness that makes it a pleasant journey even when some of the jokes aren't hitting the mark.

But most of the jokes do work. As you might expect given the film's premise, the Sweaty Robot guys are fond of absurd, surreal humor, though they're careful not to let the movie become too bizarre. It's ultimately a very realistic film, at least in terms of the characters and their emotions. Don't we all apply a little fake mustachery to our lives sometimes?