I think the narrative works because they can balance the fun and the heartwarming stuff. For example I can believe than an episode like Cookie Cats that's fun and all is in the same universe of Keeping It Together because it feels like an evolution from episode to episode, characters and interactions evolve in a believable way. >setup
As I said it was a serie that it started like a fun Sailor Moon's homage story. And many of the problems it had with the pacing of things like Lapis Lazuli was due to the fear by the Crewniverse of not getting another season. So it first started as being a 2 seasons story that worked as it's own little thing, but then it turned into something really spectacular in a way that it's believable to happen. I can feel that the kid that used to sing about an ice cream is the same that is getting in a deadly mission in space because the series made me realize that he evolves step by step. >twists? Are they convincing? Do they ad weight to the story
this would be part of the setup.
But I think the twists as you call them are what made this series recognizable and smart.
Everything was always there, everything had a little presage before being revealed to be true or false.
And that was it made it good.
The fact I was thinking at it to be real and then the show gifted me with the fact of it being true
At least for me