Exaggerated: Only the heroes end up happy; everyone else ends up miserable.
The author briefly notes that the minor characters "managed to find their happiness in due course".
Alternatively: The way the character's goals were set up, not everyone could get what they wanted without taking it from another character, so the main characters end up winning out since they're the ones everyone cares about.
Alternatively: Sadly, it's a fact of life that not everyone gets what they want when they want it or a 'happy ending'; the narrator notes this.
Alternatively: The heroes were clearly depicted to have earned their happiness through hard work and personal sacrifice, while the minor characters didn't.
It looks like the minor characters are going to be denied their happy ending, but it's stressed that the main characters make a sincere effort to ensure the happiness and comfort of those they beat out; Bianca devotes herself to setting up Paulie with a nice girl he's well suited for, Carol makes her siblings a part of her running the kingdom, and Dirk never forgets the sacrifice of the man who came before him and wins the respect of his men by following his predecessor's example.
It looks like the minor characters were denied their happy ending, but the author notes that not everything's as happy as it would first appear for the main characters; Bianca begins having an affair with Paulie behind Ace's back, Carol's siblings begin plotting against her for the throne, and Dirk's men don't respect him because they preferred the old captain and view him as an interloper.
Double Subverted: And then the side characters are all/mostly killed as part of a Sequel Hook.
Parodied: The minor characters bewail their fate, being unappreciative of what they did get, though they actually ended up better than the heroes.
Zig Zagged: The epilogue shows some minor characters happy, some miserable, and recounts how some, but not all, switched from one to the other.
Averted: Everyone lives happily.
Enforced: "We've only got a limited page count here, guys. We certainly can't explain how the people who lost out on their happy ending thanks to the heroes managed to get a replacement; it would take up a whole other book! Just focus on the main characters."
Lampshaded: "What about Carol?" "Who?"
Defied: The main characters, upon getting their happy endings, tie up loose ends and make sure all those who helped them achieve it are rewarded.
Deconstructed: The heroes didn't realize or didn't care that others would suffer for their personal happiness, even directly sacrificing others just to ensure they got what they wanted. A rift forms between those who didn't realize what was happening and those who knew but didn't care.
Reconstructed: The heroes earned their happiness through hard work and personal sacrifice; the supporting cast were all clearly given chances to do the same, but squandered or wasted them and now must deal with the consequences.
Plotted A Good Waste: The author did this deliberately to make the ending bittersweet; the more the audience thought about it, the more they would realize how the happy ending wasn't all that happy.