Part of Michael Eisner-era Disney's late period of experimentation with North American animation, 2001's Atlantis: The Lost Empire was sandwiched between Mulan, Tarzan, Fantasia 2000 and The Emperor's New Groove on the one side and by Treasure Planet, Lilo and Stitch, Brother Bear, and it's final traditionally-animated feature Home on the Range on the other. Like the majority of these, Atlantis was equally maligned for many and dubious reasons.
One grants that, of the lot it is thrown in with, Atlantis is not the unsung and inevitably-to-be-recognized classic of Treasure Planet. Nor is it in the dire dregs of a Home on the Range. Its biggest fault may only be that it entered into a culture where animated films mean a certain thing and audiences will fight tooth and claw (or dollars and cents) against being shown anything else. That is also its greatest strength.
In short, we make the untestable claim that were North America actually Japan instead of North America, Atlantis may have had a fighting chance. One might even be so bold as to argue that had the film been released in the wake of the Hellboy franchise and advertised accordingly, then it might have been the better for it (not to mention it being six years ahead of the Steampunk fad). This stems from the observation that it is perhaps less of a Disney film and more of a Mike Mignola one.
Mignola - most famous as the creator and artist of Hellboy, numerous other comics and the Amazing Screw-On Head pilot for the Sci-Fi Network - was a consultant on Atlantis, and more than that, its primary inspiration. In later interviews, Mignola recounted the discomforting sensation of walking into Walt Disney Studios and being confronted with walls of drawings and notes dissecting his distinctive style of illustration. Eventually the animators felt that to get the exact tone, they had to consult the man himself.
For those familiar with Mignola's penchant for Lovecraftian themes of ancient civilizations and eldricht horrors, Atlantis is as nearly perfect a rendition as is possible with in a PG rating. All of the quintessential Mignolaesque stuff is there, from weird monsters to angular designs to bug-eyed monumental statues and block characters, all wrapped up in a fantastically designed Edwardian setting. If there is one real complaint that we would throw at the film, it would be that too little use is made of the Ulysses submarine and its navy of podships. Their brief mission seems to have been to provide a plot device that sold toys. Which it did, to this reviewer, so its purpose was served.
Besides that, one can't say that Atlantis is particularly deep (pun intended) despite its New Age pretensions that may ultimately have more to do with its occultic Mignolian setting than a genuine spiritual message. According to the critics, the conspicuously multicultural cast can be construed as an annoyance as well. It doesn't stop that cast from having some ridiculously funny dialogal exchanges. The rest is what it was most likely intended to be: an animated summer action flick with a stylish edge. Again, its purpose was served.