"What if?" Any superhero fan worth his or her salt has pondered this question at least a few times. What if Peter Parker played hooky the day he got that fateful spider bite? What if Bruce Wayne's folks were never killed? It's not the aim of Justice League: Crisis on Two Earths to wade all that deeply into this hypothetical bog, though such ideas form its core premise. This movie ventures a guess as to what might happen if DC's finest switched to the dark side, and the results are every bit as engaging as the comic giant's best animated efforts.

There exist infinite off-shoots of our world, endless earths upon which events have unfolded a little differently. On one such planet, what we know as the Justice League has instead become the Crime Syndicate, superpowered thugs whose fists are the most iron of them all. Their reign of terror inspires a do-gooder version of Lex Luthor (voice of Chris Noth) to hop over to our Earth and seek help from the Justice League. The likes of Superman (voice of Mark Harmon) and Batman (voice of William Baldwin) are startled to learn of their sinister doubles, but not as startled as when their evil plans come to light. A bomb built by the ominous Owlman (voice of James Woods) threatens to destroy reality itself, and when faced with their equally indomitable doppelgangers, the League finds this battle to be their most pitched one yet.

Falling in line with line with the sort of animated adventure both DC and Marvel have begun to specialize in, Crisis is meant to appease all ages and demographics. However, this one may actually hit closer with younger kids because of a speedy story and loads of action that never get too intense. Not being as centered on character is no biggie, except that Crisis tries to cram some in as an afterthought. I would love to have seen any number of subplots expanded upon, and I especially wanted this flipside to the classic DC universe explored in greater detail. But Crisis hasn't the patience for these areas, so in between superhuman brawls, spontaneous subplots -- like a romance for the Martian Manhunter -- vanish as quickly as they arrive.

I can't fault Crisis too much for skimping on story, since it has but 75 minutes (less without the credits) to do its thing before moseying along. Alhough its meatier segments come about just as it starts to wrap up, the film accomplishes a good deal, particularly as it compares and contrasts Batman and Owlman's philosophies. The action skirts repetition but still carries plenty of pep, its best moments stemming from the heroes battling their own counterparts (very few of which have the ubiquitous goatee). The voice work sounds pretty standard, although Gina Torres stands out as the sultry Superwoman, and Woods gives the unhinged Owlman just the right amount of eerie calm.

Having seen Justice League: The New Frontier, I know the DC crew is capable of turning the properties at its disposal into something more than fleeting entertainment. But while I wish Crisis on Two Earths did more with its time, some storytelling takes place and at a less monotonous pace than Marvel's more recent exports. Hardcore fans can wait, but Crisis has a good shot of enthralling your own fledgling Flash or wannabe Wonder Woman at home.

MY RATING: *** (out of ****)

(Released by Warner Home Video and rated "PG-13" for action violence.)