Potential mild spoilers behind the cut:
I liked "WALL-E" very much, not because it is a cute and sweet picture, although it is that, but because it is also a story of dystopian horror. The film opens with an extended sequence detailing days in the existence of WALL-E, as far as we know the last of many of his kind, still functioning (as we learn later) centuries after the cleanup project it was part of was supposed to have been completed. Both the largely wordless sequence and the poignancy of the robot's post-apocalyptic "lifestyle" reminded me strongly of Charlie Chaplin as the "Little Tramp", particularly in "Hard Times." The worn work boot that WALL-E adds to his eclectic collection of artifacts reminded me of the tramp's shoe that Chaplin's character is reduced to eating in "The Gold Rush." Casually embedded in this sequence is the grim indication that WALL-E has "cannibalized" his fallen cohorts to keep running: we see him compare his worn treads with newish ones still on an inoperative robot. In the next scene he is wearing the newer treads, like a Civil War soldier having scavenged dead men's boots.
WALL-E encounters the environmental probe robot EVE, and, after another sequence of Chaplinesque misery tending "her" when she is inactive, succeeds in following her to space, where another sort of dystopia is revealed. Due to the "full-service" program of the refuge ship "Axiom", humanity have all become big, blobby babies, who don't eat anything that can't be sucked through a straw, and live so hypnotized by their constant interactive chat that they are oblivious to their own surroundings.
The plot plays out to what, in my mind is a very dubious happy ending, by way of substantial thematic borrowing from "2001: A Space Odyssey," and, more subtly, the underrated "Silent Running." There are also stylistic nods to "Star Wars" in the design of many of the robots aboard the Axiom, with traces of "Star Trek," (a five-year mission), "Alien," and "Dr. Who." (And I know I've seen the design of the "Axiom" on a 1990's era SF novel cover. I'm sure the name must be an allusion to something, but I'm deuced if I can figure it out--.)
Acting is an interesting issue, since the two protagonists communicate by single words at a time and don't seem to use more than a total vocabulary of about five words each. Therefore, it is a bit of an accomplishment for the voice actors Ben Burtt and Elissa Knight (WALL-E and EVE) to manage to get as much expression as they do. The bulk of the acting load is carried by the animation, who manage wonderfully well with a head made of East German surplus binoculars, in WALL-E's case, or mere blue pixels on a black screen for EVE. The animation is routinely beautiful except when it is exceptional, as when showing moving reflections on a shiny curved surface. (A further bad sign for real actors: the character of AUTO is credited as being voiced by MacInTalk, an Apple text-to-speech program!)
All in all, a fine movie and a must-see. I just wish I had more belief in the happiness of the ending. Pizza plants, indeed!