Those who don't like the movie will love Linus/Minus' overacting. Those who like the movie will definitely love his overacting.
George Lopez was clearly under no illusions about the kind of movie he was in, and naturally the entirety of his screentime as Mr. Electric is an extended hamfest. And his scenes as Mr. Electricidad are downright unkosher.
"I did NOTnote or alternatively: "I did NAUGHT" ! Mr. Electric, send him to the principal's office and have him expelled!!"
"You're in MY class, not the other way around! I know EVERYTHING! And you... know nothing."
"At the end of class, both of you will report to the principal's office...WITH YOUR PARENTS!"
Some people on tumblr also had the idea of mixing up the words in the title, so they came up with "Lavashark and Boygirl".
Narm: Several instances, mostly the ridiculous faces Mr. Electric keeps making. Though it could be justified as his faces seem to be on purpose.
Also, Max's parents' horrendous acting when admitting their love for each other in the climax of the movie. Dear God...
Narm Charm: Robert Rodriguez based the film solely on dreams and drawings from his young son. Naturally, there was absolutely no way that the movie could be anything but an extended cheesefest with more holes than a sieve in the writing, made to appeal to elementary school-age kids and no one else... and the way it shamelessly embraces all this is why some people find it so enjoyable.
So Sharkboy gets his own origin story, having been raised part of his life by sharks. What's Lavagirl's backstory? Never explained in the movie.
The psychological aspects of Max and his dreams aren't really explored much outside of surface references. The movie's overall message is supposed to be, "as long as you work hard, dreams can come true" as well, so this helps muddle it, but Max's parents are fighting a lot and thinking about getting a divorce. Max is cognizant of this and it's represented in his dreams that he's worried about them. He even imagined Sharkboy, Lavagirl, and an entire planet to escape reality and convinced himself they're real. Until they show up, the movie treats them as such, so the setup of the movie could've involved what a kid goes through when they're worried about their parents splitting up, but the film gets wrapped up in dealing with Max's bully and proving to him his dreams were real.
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.