I don't think I'll be able to finish *w* Quintet before release, it's really long. If you've pre ordered it already I assume you know what you're getting into and I'd recommend keeping the preorder, personally. I'll try to have some form of review up but I'll slap this here for those interested:
-Combat system is great, very complicated, so complex you can ignore a fair few mechanics and still get by fine most of the time.
-FFX style turn system where you manage the delay of your attacks and turn order, combo attacks when allies turns line up
-Multiple actions per turn based on weapon proficiency
-FFX style "sensor" that shows elemental weaknesses, and also status weaknesses, and abilities. You get a crazy amount of info mid battle and it's pretty great
-Characters have default roles but you can easily break out of them just by switching gear and learning skills
-Nothing is TOO broken combat wise, other than special skills sorta (roughly EXE skills from Neptunia). Managing SP is very important.
-Game is too easy for too many chapters, playing on hard might be best (I haven't tried hard yet). It just started being kinda challenging in chapter 6 (9 chapters I think). There is also an easy mode for babbies
-The story is basically what you expect for better or worse. Not as good as Neptunia in terms of characters/story/art style either. Far less references.
-Missables, but if you know they're coming it's not a big deal. Do all sidequests before advancing story, EVER
-Fields are way bigger and more interactive than Neptunia. You revisit often with new abilities to get some extra goodies. Map movement is fast, with fast travel points, and an unlockable even faster movement speed
-There is a button to mute the mid-battle singing (a limit break sort of deal) and the actual idol show stuff is entirely optional/skippable
-I'm 56 hours in, at chapter 7 (of 9? 10? I think?), like 10 of those hours are from leaving the PS4 on overnight, but it's pretty long. Or, JRPG length perhaps I should say
...that was supposed to be short. I don't do short well