Twenty Thousand Leagues is great fun, easily the best live-action Disney ever made.
Kirk Douglas made for an enjoyable Ned Lands, where he plays himself--athletic straight shooter, no pretensions; Peter Lorre has the Sancho Panza role, and he makes of it what he can, giving us beleagured common sense caught between Lands' lowbrow slapstick and the professor's fine ideals. He even persuades us that there's a real friendship growing between his character and Lands--that bit of business where Lands sweeps his hair back with one hand and Lorre has to slick it back down, I wonder who came up with it, was it in the script or did either Douglas or Lorre improvise?
James Mason gives the film what tragic depth it has, of course; his brooding Nemo is both idealist and cynic, and he deftly suggests either one or the other with every other line of dialogue, and you don't blink, you buy the contradiction. I think it helps that Mason gives every line the same weight and emphasis, the same measured, immaculate delivery, suggesting he believes in the potential of man exploring and understanding nature the same time he believes in his insiduous nature (what's really needed is someone equally compelling to point out to Nemo that man is part of nature, and as such he should make the effort to pull himself together).
Wonderful performances, but really the star of the show is the production design. Fleischer has a rearview window that at times acts like a film screen, showing us, say, the drama of Lands and his friends being towed into the sea to drown; even better is the giant iris that opens up like a movie camera's to present the wonders of the ocean--it's Disney's fascination with nature speaking, showing us what we could see if we only open our eyes, and I think an emblematic image of the magical possibilities the ocean holds for us.
If the design is the real star, then the Nautilus is its greatest triumph, part giant iron-scaled fish, part steampunk techonology (not from Verne's point of view, of course, but definitely from the filmmakers') come to humming life, and all cinema magic; what makes the vessel so memorable is that eerie green glow it gives off; it reminds you of the luminescence you see when huge creatures stir the ocean depths.
That huge squid was impressive, even if it did move backwards (couldn't they tell just from the way the creature was designed?).