Simple, it says a lot by showing few. And that was star wars is, a simple really well strutured myth-like story.
So, a good story for now, as we only attempt episode three.
Seems preparing, explaining, enhencing the new trilogy universe by describing an interresting period : the remaining parts of the empire and the complexety of building a new republic, with interesting characters.
A side story where the Force is not forgotten, is what I expected for a Star Wars Story. I was pretty dissapointed by Rogue One for example as it was only a military like movie within a Sci fantasy universe.
And a side story really emotional at some points, with a masked main character abled to express feelings and complexity.
It's also well filmed, produced even if you can feel sometimes a lack of budget.
It will probably allowed the new trilogy to make more sense, will see.