"Simple" isn't intended to be derogatory, the anime is enjoyable, fairly well put together and there is enough character development to make it worth the watch, but the overarching story is not complex.
Unless this is the first anime you've ever watched there won't be any serious surprises, and as others have stated it watches like a JRPG which I think is one of its charms.
There is good, evil, a hero and all of the challenges that could make for a boring trope filled series, but instead of being a cliched snoozefest "Grancrest" balances the flow of the series almost perfectly.
It's a great show to binge and what I find most satisfying is having closure, to many anime series are left unfinished.
Pro's:
- Good score / soundtrack.
- Simple but enjoyable story.
- Enough character development for engagement.
- Very little "filler".
- Closure.
- Solid English dubbing.
Con's:
- Predictable (I enjoyed it, but it could be a turn off).
- Lower quality / inconsistent animation at times.
- Dubbing / Subtitles don't always line up (Court ranks for example).