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.
YMMV: A Troll in Central Park
Alternate Character Interpretation: It is possible to see Stanley as not so benevolent troll, considering he dreams of a land where all trolls are essentially copies of him (even if supposed to be "good") and, in the end, he covers New York in vegetation. Whether he is simply delusional or actively malevolent is up to the viewer.
Big Lipped Alligator Moment: The boat ride suddenly enters Stanley's dream land which he apparently created out of nowhere, we see all kinds of happy things that have no relevance to the story, and when the sequence is over, nobody mentions it again.
Inferred Holocaust: The movie ends with all of New York being engulfed in vines and flowers. It's meant to be heartwarming, but ends up looking like some sort of supervillain takeover, or a scene right out of Life After People. It's not even made clear if it's just supposed to be another dream sequence.
Glurge: Stanley's vision of a "perfect" world, even more so than everything else in the film. Basically, it's a sickeningly-sweet world filled with trolls who all look and think exactly like him.
Rooting for the Empire: The villains of the film, Gnorga and Llort, are far more popular and liked than the actual protagonists, Stanley in particular.
Gus on a smaller scale. He spends most of the first part of the movie as a kind of Anti-Hero. And he's the one willing to fight for his ends, unlike Stanley, the supposed hero who would rather cower.
Ron the Death Eater: Stanley gets this treatment from some viewers, largely due to his glurge nature, not to mention the similarities between his actions in the films ending, and the lost ending to Little Shop of Horrors.
Llort's hand waves regarding why he would rather not just let Gnorga stone Stanley*
Because the troll populations are declining, and executions should be avoided if possible
would have made for a fascinating subplot, which would give Stanley additional motivation for his goals as well as add complexity the villains. This whole film is full of originality that's sadly left unexploited.
Ugly Cute: Pretty much the film's entire design aesthetic.