Film festivals, by their nature, tend to exhibit flicks that would not be shown in your standard Indiana multiplex. So, amidst what has become an increasingly crowded local film festival scene in recent years, a festival that calls itself the Boston Underground Film Festival (B.U.F.F.) has some explaining to do. “Underground” quickly conjures up the image of trench-coated filmmakers tentatively handing their reels to festival officials in some rainy alleyway just after midnight—so there must be some brand of rebellion in their work. Boundaries must be broken, ideals must remain reasonably uncompromised.

Tall order? Well, consider that last year, B.U.F.F. lauded an locally made short called Titler, an absolutely brilliant low-budget singing-Hitler-in-drag conceit, consummately crafted in every respect. Not content to simply croon vulgar showtunes for mere shock value, the film’s protagonist alludes to genuine psychological flaws within his character, giving his songs a thread of narrative while breaking barriers of taste that only shock jocks and the Wayans Brothers dare approach—and for far less thought-provoking ends.

In this year’s B.U.F.F., which runs from February 20-27 at various locations around the city, I’ve yet to see anything capable of matching Titler’s expertly skewed worldview—and, really, isn’t a different view of life what we’re looking for when we go to the movies? Still, the 2001 festival does offer intermittent pleasures.

The 35mm Shorts program, which opened the festival Tuesday night at the Fenway Theater, was a typically mixed bag. Its indisputable highlight was Heart of the World, Guy Maddin’s glorious take on early Russian melodrama that won the award for Best Experimental Film from the National Society of Film Critics last month. As Maddin cuts from one shot to the next with uninterrupted speed, the film feeds the viewer a surprisingly satisfying plethora of visual information and symbolic imagery; you’d think that the quantity would smother your mind, but the film’s tried-and-true love story leaves one free to turn one’s attention from the film’s plot to its most striking images. I’ve seen Heart of the World three times, and it has never failed to leave me less than exhilarated.

Other shorts in the program included Dog Days and Humpty Dumpty Land, both of which dealt with the terrors of present-day war, the former from the civilian point of view, the latter through the eyes of a half-sane soldier. Humpty Dumpty Land has moments of surprising grace, handling reds and greens with visual and symbolic skill, and creating an unnerving atmosphere largely around water: the movements of tides, the lazy formation of tiny pools, drip by drip and the glassy surfaces of puddles that dimly reflect a prone man’s bloodied head. Dog Days, an uncomfortably heavyhanded, if moderately haunting, post-apocalyptic tale, fared more poorly. The film centers around a family’s reaction to the arrival of a man who has taken on the persona and the appearance of a dog. His desperate humiliation of himself for survival is wearily mirrored by the portrait of his host family turning savage in the face of society’s collapse. The cinematography is stunning, though.

Lint People, meanwhile, was merely cute, an animated trifle about characters made from those useless bits of fuzz and stuffing that come loose from your clothes in the dryer. If cleaning the lint filter is the highlight of your lazy Saturday, then the film’s final shot will make you break down and weep tender, knowing tears. Otherwise, don’t rush out.

Outside of this shorts program, the chief delight of the festival is Bill Plympton’s taste-impaired animated feature Mutant Aliens, which delivers what its title promises and more. Its genetically altered space animals stomp, impale, gulp down, and otherwise commit murder in the name of justice for Earl, the story’s embittered astronaut hero. Earl’s chief opponent, the money-minded space official Dr. Frubar, soon learns that an antagonist who relies on the support of ad money and horny secretaries can only advance so far. Plympton’s inventive mind is perceptive enough to create clever scenarios with some sort of reason to them; in the best sequence of the film, he conjures up a planet inhabited by intelligent body parts, but has the wit to craft a discordant societal structure around them. Earl takes up with the planet’s population of tiny-limbed noses, and together they battle tongues, lips, thumbs marching stoutly in formation, and eyes riding hands and feet into battle, their toes and fingers blazing like machine guns. Ultimately, Mutant Aliens gives Plympton the opportunity to cram into an 80-minute time span every ingredient that one could ask for in a cartoon: blood, gore, sex, fast cars, an orbiting billboard the size of Oregon, and a peppy Christian ditty titled “Can’t Drag Race With Jesus.”

I’m also taken with Out the Fire, a charming animated short depicting skeletons dancing and riding fire extinguishers through New York City. There’s something infectious about its crude drawing style and its jaunty Caribbean soundtrack. Where Monsters Lie, a light, brief tale of monsters living among us, is even more crudely drawn and only marginally interesting. Pleasureland is an uncompelling clunker of an erotic sci-fi story, following the exploits of an man who stumbles upon a video store whose adult tapes are made flesh by his VCR. The short also features yards of cable, black goop and tiresome irony.

So, if you’re keen on going to the B.U.F.F., don’t expect it to be Sundance, but rest assured that it does offer some quality product on the whole. Heart of the World is showing multiple times throughout the week, and Mutant Aliens is showing at midnight tonight at Fenway; see both if you can. For a list of all festival films and showtimes, visit http://www.bostonundergroundfilmfestival.com/.