There are certainly moments in "Time Bandits." In one of them, Ralph Richardson, playing God in a faultless gray suit, replies to a naive compliment with, "Well, I am the Supreme Being, and I'm not entirely dim."

In another, he falters when asked why evil exists in the world, and finally replies, "I think it has something to do with free will."

Unfortunately, God and Sir Ralph appear in only one brief scene in this film, which consists of the dream of a little boy living in a modern, mechanized society, who goes to sleep after his history lesson and imagines that a band of dwarf robbers takes him back across time.

The dream is basically rather goofy fun, but each part is strung out to the point of tedium. We see Napoleon trying to compensate for being short, Agamemnon not noticing how much dislike Clytemnestra puts in her glances, and Robin Hood affectedly making like a man-of-the-people politician. If each of these had been fast bits, and more such episodes added, it would have been a snappy movie.

A serious drawback, at least for pedantic parents who might otherwise encourage their teen-agers to see the film, is that the boy is not much of a history student. It's one thing to take liberties with characters in order to satirize them, but quite another to be so ignorant of these characters as to intrude annoying inaccuracies. Mycenae, for example, is pictured as an Biblical village, with mud huts and palm trees, and we are told that Agamemnon is reigning there long after the Trojan War. He adopts the modern boy, no mention being made of his thus acquiring some rather formidible siblings with a deep sense of their own family rights. This is worse than garbling history -- it's forfeiting a chance for hilarity.

In addition to Richardson's supremity and a correspondingly bad impersonation of his opposite number by David Warner, there are funny vignettes provided by Shelley Duvall as a medieval lady, John Cleese as Robin Hood, Sean Connery as Agamemnon and Ian Holm as Napoleon. The little boy, played by Craig Warnock, is innocuous, but the drawfs, played by David Rappaport, Kenny Baker, Jack Purvis, Mike Edmonds, Malcolm Dixon and Tiny Ross, are deft comedians. TIME BANDITS -- At the AMC Carrollton, AMC Skyline, College Park, Jenifer Cinema, Laurel Cinema, Loehmann's Plaza, Roth's Manor, Roth's Tysons Corner and Springfield Mall.