The trailers don't do the movie justice actually. It appears as some thing simple; but what they don't show is how much that simplicity is actually root of its complexity. The character development is AMAZING... the robots are flawless and a nice contrast to the organic shape of the humans. The contrast of the two main characters... wall-e and eve are GREAT. Wall-e is given a rigid retro-robot feel similar to Short Circuit that purely represents masculinity while Eve is given a simple egg form to show the new age of compact technology as well as the root form of femininity. The labor skit was hilarious.
The also has a nice feel similar to the old time silent pictures. There is very limited dialogue between the main characters so you rely on their expressions and actions which are very slapstick and quirky so you instantly fall in love with them. I found for an animated film about robots Wall-e is VERY relatable. If you've ever been one of those that is geeky, awkward, been in love, and has tried soooo hard to get that persons attention... you'll understand.