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.
Anti-Climax Boss: Subverted. Dennis is built up as a major threat but crushed by the Cyclops moments after he finally catches up with the heroes before he can do much to them... Then he comes back and the actual fight with him takes place.
Not to mention that brief Heroic BSOD at the edge of the trench, where SpongeBob realizes how immature he is for his age. Hearing the guy sound so panicked and frustrated with himself is quite a shock.
Possibly the best example would be Plankton successfully framing Mr. Krabs for stealing the crown, with a simple phone call. But what really makes it it Plankton smirking, listening to Neptune scream.
Plankton: "Plan Z. I love Plan Z!"
Memetic Mutation: Surprised Patrick◊, from his reaction following Always a Bigger Fish. Pretty odd, considering the fact that the movie came out nearly ten years ago and has only recently become a meme - and the fact that SpongeBob was there pulling the exact same expression, yet he does NOT have the same Memetic status as Patrick (a fact that is lampshaded in this image◊).
Moral Event Horizon: Plankton definitely crosses this when he steals Neptune's crown, frames Mr. Krabs for it (knowing very well that he'll be executed), brainwashing and enslaving Bikini Bottom and hiring Dennis to kill SpongeBob and Patrick. He takes it even further at the climax when he brainwashes King Neptune to not only kill SpongeBob and Patrick, but also kill Mindy, his own daughter.