The usual "more sequel less interesting" didn't aply to the Hyperdimension serie
The story is really deeper than the first two series the nation order (Planetune, Lastation, Lowee and finally Leanbox) is used to make rational story not cut in various part, but in a more linear form.
The new scout system help the player during the story event by giving bonus xp or even new items, most likely a waste of money at first it finish up by being a really interesting as up your sleeve once you mastered it.
The battle system didn't really change from the previous game except from the fact that the sp aren't in the game anymore and was switched with an exe gauge instead. The exe system is really more useful than the sp gauge was, the exe bar didn't diminish to the third each time you finish the battle, but instead is really slow to fill, in a way it encourage the player to not simply run the dungeon avoiding the fight. Using one exe gauge segment can also be used to cause an exe attack that is pretty much an overkill attack with a fancy animation. So the player can choose between keeping it gauge to deal more combos or using it to put an end to a fight or cause serious damage to a boss.
The new challenge system is also interesting, as it say the game have little challenge all the characters can complete during the dungeons and fights. Those involve basic things like receive an amount of damage and just jump, yes this game finally let the character jump in the dungeon as little it can do some of them make the jump capacity a way to take shortcuts and such.
The game also has an evaluation system that is for the least annoying. Each time you finish a chapter (start at chapter 2) you are noted on a mark of 10 by the game "creator" on 4 things; the quests completed, the shares, the scout system and the number of mobs defeated. For the first three chapters the player will most likely get horrible marks because the quests are horribly unbalanced. The game let you control the other cpu's extremely fast and so you are at the start stuck with the share problem. By share problem I mean to how you should split the shares so your favourite cpu's get the most power when in HDD. The game seems to only take Planetune share into account and it quite troublesome because it does boost 2 cpu's power but the backfire is that it weaken the others. The quest completed note resolve about how you should make a crazy amount of quest by chapters, good for level powering and money earning, bad for the pleasure. For the other two it really simple use the scout as much as you can and defeat all the enemies in your way and you get the best mark, just don't rush the end of the chapter.
The game also have a sort of pantie shot special skills, almost all the first attack skills of the characters involve a panties shot and like it wasn't enough a little blinging noise is heard at the moment the panties flash, some players might like that, I am not one of them...
Overall the game mechanic, story and animation are the better of the series, I recommend this game to anime fans and all console fans. With several wink to the old console and company console flop this game keep it humorous and light hearted feel. The second sequel of the series is a "to buy" game for all the fan of the 2 previous titles.