Took me 14 hours to beat (1000G). The game is pretty good but there are a few things that keep it from being a truly awesome game.
Combat is too easy. Difficulty was alright at the beginning but after the first boss there's basically no enemy that can kill you, even if you don't upgrade your defense and attack. On the plus side there are so many characters to unlock, so you could theoretically change up your party quite often, but since the combat is so easy there's no need to. I just chose the characters with the highest strength and killed most enemies pretty quickly (even if some act like sponges) while having one healer. They should've included sequences where not all team members are available and you're forced to play with some other guys.
There's too much backtracking in the game. While this is not uncommon for Metroidvania-like games, you have to pretty much play through a whole region again only to get back to the part which you previously couldn't access. The few fast travel points (which you begin to unlock during the middle part of the game) don't really help much.
On the plus side, the platforming can be pretty challenging as there are tons of abilities that will unlock as part of the main story which can make platforming quite complex. Visuals are top notch. Many voiced lines, some anime scenes, simply feels like an indie game with a high budget. Length is alright as well. There are a few more side quests which can unlock even more characters to play with. Story is enjoyable too.