The newer episodes (as of May 2005) are slightly different from the episodes we've seen before the movie, not that it's completely wrong. The comedic timing and some of the character designs are two of the main aspects in mind.
But have you noticed SpongeBob? He's always been a versatile character, physically and emotionally. But he seems a little more vertical now than he was before.
Maybe we should start calling him "SpongeBob Rectangle Pants"?
