These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Acting for Two: George Lopez plays several roles in this film. As well as the obvious Mr. Electricidad and Mr. Electric roles, his voice was deepened for Tobor and pitched up for the Ice King.
Anvilicious: All of the adults are intentionally made to come off as this.
Ear Worm: "Close your eyes, shut your mouth, dream a dream to get us out, dream dream dream dream dream dream..."
Fridge Brilliance: The Conspicuous CG is one of those tropes that breaks the illusion, and therefore the viewer has no suspension of disbelief... but that's the point; you're not supposed to think Planet Drool is real. The audience is just like the rest of the adults in the film that think Max's dreams are ultimately fake. It's not until Sharkboy, Lavagirl, and Mr. Electric come to Earth at the end that their existence is validated.
Lavagirl's representation in the real world (besides Max's mother) is a lava lamp.
The movie's story did come from the director's son, Racer, who was fairly young when it was written. A lot of viewers tend to forget that.
Tear Jerker: Max crying over Sharkboy and Lavagirl, who appear to be dead.
Toy Ship: In-universe examples: Max with Marissa and Lavagirl with Sharkboy.
The Woobie: Max. He's a bully magnet and just wants to be left alone to dream in peace. Interestingly inverted at the end when his own invention makes him realize that he's only been dreaming for himself and didn't care enough about others, implying that everyone else needed his help and The Woobie was actually all of them.