Fantasy Mission Force knows that it sucks. Director Chu Yen-Ping once remarked that rather than being any kind of real artist, he was instead "a movie factory that puts out products to match the season." Jackie Chan is only in the film to repay a debt to Ping, who had paid a large sum of money to help settle a conflict between Chan and director Lo Wei. The opening scenes of the film quickly establish a knowing and willful lack of regard for originality, narrative continuity, and historical detail. This is not the work of a well-meaning but deluded 5th-rate outsider artist, although it does have that surreal, hallucinatory quality of many of the best worst movies out there.
Hong Kong cinema of the late 70s and early 80s carried a thread over from Depression-era Hollywood: Audiences may not have been able to afford many trips to the theater, so films were often made to have a little bit of everything. A dash of action, a bit of comedy, a musical number, a romantic sub-plot, and possibly a few scenes completely lifted from other popular movies. Fantasy Mission Force takes this approach to its (il)logical conclusion, making a complete hash of its plot, setting, and characters in the service of "Hey! Hey! Um...look at this!"
Fantasy Mission Force also occasionally manages to be charming in its comedy and hilariously badass in its action-posturing. Most of the fight scenes, while not up to the standards of Hong Kong masters like Lau Kar-Leung, are much more crisp and acrobatic than anything found in the West at the time.
The first half of the film riffs on Dirty Dozen and Magnificent Seven, assembling the titular strike force from criminals and oddballs and then standing back to see if these disparate characters can coexist. It loses steam in the second half as it genre-hops from one pulp scenario to another, and by then viewers may be a little tired of all the chaos.
Even with a dragging third act, Fantasy Mission Force is a competent, fun, surprising, and exciting total piece of garbage.