"Superman II" should coast to success on the enormous reserves of good will created by its playful, stirring predecessor. After a Christmas 1978 debut, "Superman" became the top attraction of 1979. It now occupies seventh place on Variety's list of all-time box-office hits.

Nevertheless, the sequel gives more cause for alarm than satisfication. An auspicious beginning appears to degenerate into a premature collapse. The only aspect of "Superman II" that seems calculated to preserve the good will is Christopher Reeve's charm in the dual role of Superman and his shy mortal front, Clark Kent. Outside the dazzling aura of Reeve's image there's a dreadful lot of tarnishing and wrecking going on under the laborious direction of Richard Lester.

Opening today at several area theaters, "Superman II" gets off to a fast start (in part by recapitulating the plot of the original film in the credit sequence), only to evolve into a curiously absent-minded follow-up. The production suffers from a tacky veneer, symbolized most conspicuously by some hideous composite photography in special effects sequences and by Ken Thorne's anemic reorchestrations of John Williams' original score.The impression that certain things are being done on the cheap is difficult to shake.

The screenplay leaves wide motivational gaps and unexplained reversals of fate. The most perplexing baffler: How does Superman recover his superpowers after we're told that he has rejected them irrevocably in order to enjoy mortal romantic bliss in the flinty embrace of Margot Kidder's Lois Kane? It appears as if an explanation was lost when the producers cut scenes featuring Marlon Brando, who was already suing them for his profit percentage on "Superman" and would have been eligible for the same theoretical cut on the sequel. My affection for the original film was a vivid memory when I entered "Superman II." It seemed a wantonly abused memory by the time I trudged out. Curiously, the feeling is the opposite for several friends and colleagues who weren't as enthusiastic about the original.

Let's examine some of the evidence. Both movies flirt with grandiose disaster, and both are spared by the grace of Reeve's winning embodiment of an outrageous herotic dream figure. In retrospect, the first movie seemed fortunate to have survived its lengthy introductory chapters before Reeve made his entry.

Reeve sustains the sequel although the prevailing tone has gone from fresh and exciting to defeatist (this may be Lester's input), far more appropriate to the dismantling than the reaffirmation of a heroic myth. Since the filmmakers act almost brutally determined to put the hero at a humiliating disadvantage by negating his supernatural strength, you tend to fall back on Reeve as the only heroic resource in sight.

Superman may be a more wholesome all-American joke than Lester feels comfortable exploiting. At any rate, there's nothing humorous about the three villains who confronts Superman in the sequel. Indeed, they put a creepy new complexion on everything. They're the Kryptonian seditionists who were banished in the opening sequence of "Superman" -- Terence Stamp as the mastermind Zod, Sarah Douglas as his butch-punk henchwoman Ursa and Jack O'Halloran as a weak-eyed giant called Non.

In the first and last clever plot twist in "Superman II," this kinky trio of despots is accidentally freed from bondage when Superman saves Lois' life and spares Paris a nuclear disaster by hurtling a terrorist bomb, rigged to an elevator in the Eiffel Tower, into outer space. When the bomb explodes, shock waves shatter the mirror-like "zones" tha confines the villains.

Zod, Ursa and Non find their way to Earth, where only the powers of Superman could possibly defeat them. Unlike the funny villainous trio from "Superman" -- Gene Hackman, Ned Beatty and Valerie Perrine, whose fleeting appearances in the sequel kept reminding me how much I preferred and missed them -- the invaders from Krypton are a sheer pestilence, escapees from some unimaginably nasty leather bar in a distant galaxy. You don't want to linger around these ruthless despots. You want to see them crushed, fast.

The details illustrating their reign of terror tend to strike at peculiarly vulnerable patroitic feelings -- they casually kill a team of lunar astronaunts, deface Mount Rushmore, wreck the White House and force the president (E. G. Marhsall in a ludicrous toupee) to kneel and pledge allegiance. All of this is kinkier provacation than their costumes, and the movie leaves a sour aftertaste by neglecting to clean up the oddly perverse wreckage.

What is Superman doing while the gang from Krypton makes a shambles of his adopted home? He's tucked away in a romantic subplot whose complications are exposed as arbitrary delaying actions. Lois and Clark are assigned by Daily Planet Editor Perry White (Jackie Cooper again) to pose as newlyweds to investigate some honeymoon hotel swindle in Niagara Falls. White sightseeing, Lois Decides to test her suspicions about Clark by jumping into the rapids. Inexplicably, he fails to jump in after her, and she manages to grope her way to shore while he fusses. What makes this episode especially confusing is its immediate aftermath, in which Clark does indeed reveal his true identity and then whisks Lois off to the Fortress of Solitude.

The filmmakers persist in ignoring the significance of things just shown us. At the Fortress, Superman has a powwow with the spirit of his mother (Susannah York), who says that cohabiting with an earthling will require the surrender of his superpowers once and for all. It seems a curious catch, and one is further surprised by Lois' failure to make a noble self-sacrificing gesture when she overhears the conversation.

However, Lois doesn't let out a peep, Superman undergoes some desuperfying process and the happy mortals are soon found snuggling in a giant seashell of a bed that looks even funnier than the think-pink furnishings back at their hotel suite. By the time the lovers straggle back to civilization, where Clark is promptly punched out by a bully, the invaders are intimidating the world and asking where's this Superman everyone keeps babbling about.

Very little urgency emerges from Lester's crosscutting between marauding villians and oblivious lovers, but the bottom falls out when a now alarmed and guilt-ridden Clark schleps back north and somehow returns from the Fortress with his lost powers restored. Obviously, an obligatory explanation has been left out. The only pausible explanation is that it had to be a scene in which Brando reappeared as Jor-El and made his boy super again.

The continuity remains as ragged after Superman goes into action against the villains. There's an elaborate and often spectacular sequence of battling over the rooftops and along the streets of Metropolis, which takes a fearful pounding. The clash drags on and on but still nothing decisive happens in Metropolis. So it's back to the Fortress for a private rematch, which is finally settled after a good deal of coy hiding-and-seeking and possum-playing.

Although the producers talk of a "Superman III," they've compromised the series with this excess of arbitrary plot contradictions. Even the pleasing idea of Lois and Clark as a couple linked by knowledge of his identity is eventually written off as another fake-out. What seems to have been lost is the straightforward heroic exuberance of the original film, despite Reeve's gallant and endearing efforts.