Riddle me this about Batman Forever:

How can a high-voltage, mega-monster movie with so much going for it - from the fabulous forties-futuristic sets to the deliriously funny Jim Carrey as a mad villain - turn into such a big Batbore?

The insouciant Kilmer even tosses off a few witticisms that might have left Keaton tongue-tied. "Chicks love the car," he jibes about Batman's sex appeal. But there just aren't enough of these lines to turn new director Joel Schumacher's Batman Forever into camp comedy.

And Schumacher, despite his success with the dark side in movies such as The Lost Boys and Falling Down, sucks the life right out of Tim Burton's subterranean psychology themes from the first two instalments.

Instead, except when Carrey is shamelessly chewing up the scenery and stealing all the attention with his delightfully demented physical comedy, the film is a heavy-handed, overwrought, B-movie thriller about Batman's struggle to save Gotham from two villains.

One is the gun-toting psychotic Two-Face, played by Tommy Lee Jones, and the other is the mad scientist The Riddler, played with such gusto by Carrey. There are too many car chases, too many explosions and not enough character interaction to make us care.

Batman/Bruce Wayne both have a single new love interest, a psychiatrist. Which is appropriate because these guys/guy need help. She's Nicole Kidman but she brings none of Kim Basinger's wonkiness nor Michelle Pfeiffer's growly sensuality to the Batcave.

Meanwhile, traditional Batman sidekick Robin finally makes his debut with Chris O'Donnell stepping into the tights. Don't blame O'Donnell either for the Batbore catastrophe. Despite the homoerotic overtones of the bulky, high-gloss, anatomically incorrect, rubberized superhero suits he and Kilmer don for the movie's big climax, O'Donnell actually humanizes his role as Robin and gives the movie its only spark of real emotion.

His post-punk Robin is an angry young acrobat who saw his family wiped out by Batman's arch enemy, Two-Face. O'Donnell makes us feel it.

But Batman Forever falters right here. Superhero movies are only as good as their villains. As Two-Face, the irascible Tommy Lee Jones simultaneously gives two of the worst performances of his career. He struts. He screams. He hollers. He's hell on Earth.

Combine those histrionics with Kidman's bland emptiness and you've got trouble. Sexless and sparkless, Kidman is like a beautiful butterfly pined to the walls of Batman's brain. Bats eat insects.

I'm not saying Batman Forever is guano. But it is not the Batman Tim Burton created and it's not forever.