I often saw this game described as "Sailor Moon: The RPG", which I guess is an apt description to a point. Probably a bit too flattering, though. It does have transforming "magical girls" accompanied by very similar transformation scenes (that you thankfully don't have to watch every time), so the inspiration is pretty clear here. But other than that it's mostly a "high school simulation" game with a story that's more or less about people's strong emotions during puberty and friendships and such.
It takes its cues from Persona in a way, in that you have a kind of S-Link feature. You can invite your friends to dates, but with no romance options (it is, of course, an all-girls high school). With an increased friendship level you get to level up your character (there are no traditional experience points) and you can get "fragments" with which you can augment your skills. The scenes are your average blah-blah about going shopping or whatever else places they visit. There's no real characterization happening here, most characters hardly ever evolve beyond their own quirky characteristic.
Even aside from those dates, there's a lot on focus on interacting with your friends. You can use your smartphone to talk to everyone in a messaging application that look kinda like LINE. There's a blog that retells the recent story (run by a friend) and some mini games. What's kinda interesting is that everything that happens on your phone is completely pointless as far as the game itself is concerned. You don't "get" anything out of it, other than the conversation or the mini games themselves. There is, for example, a sort of hide & seek kinda game, where one of your friends gives you hints on where to find her plush bears she hid in the school. You can go out and look for them, but you can't pick them up or interact with them in any way, they are just there. In video games you usually expect rewards for everything you do, so I saw a lot of confused people about these aspects of the game and I have to admit I also looked online if there's any "real" point to it all, but in the end it's fine to have it like that, it's just unusual. The monster raising mini game gives you a trophy, though, so I guess there's that.
Combat happens in a separate "realm". You can go there whenever someone's emotion run amok and it's here that you're transforming into your "magical girl" persona. Battles are your typical Gust style turn-based system. That means everyone is on a timeline and whoever gets to the center, gets to act. You can push back enemies to delay your turn and, kinda like in the Atelier games, you have some skills that you can put onto the timeline that get activated on their own. There's nothing really special to it, it works well, but overall the game is rather easy, so you rarely have to play with status effects or pay much attention to resistances and stuff like that. Later on you get some extra skills you can activate at any time that allow you to act faster or defend, those drain a special gauge. You can also call in your NPC friends to help you in battle, but this is only possible in boss battles.
Skills are earned by leveling up your character and each skill allows you to equip a certain number of fragments that can enhance your skill or character. You can improve these fragments through a simple crafting system which is where items come into play. There's no money or shops (apart from the school cafeteria) in this game, so you have to get all your items from enemies, gathering or as quest rewards, which can be a bit tedious since you don't always have access to every area, but overall it adds a little more purpose to the whole game, so it's very welcome. Technically you can also use items (I think!?), but it seems pointless to do so, you hardly ever even need your support skills.
So, basically, your usual game flow, once the game gets properly going (which takes a while), is this: You get some story part which usually involves going through a dungeon and collecting some stuff and a boss fight. Then you go back to school and have "free time", here you can do sidequests, which either involve crafting certain items or going through a dungeon and killing certain enemies or collecting certain things, or you can work on your friendships. You get points for doing sidequests and once you reach enough points you have the option to advance the story, if you want. It all works well enough, sadly, the writing isn't really good enough to keep you interested in these characters, so hopefully you get enjoyment just out of improving your stats. It is a rather repetitive game, but that's okay. It is a low budget game after all and it shows. There are only very few different enemy types which each have about four or fives variations that all look very similar. There seem to be only a handful of dungeon layouts that repeat over and over during your quest. So you'll be seeing a lot of the same. So there's a lot of repetition in every aspect of the game, which means your enjoyment highly depends on your tolerance of such things. It kinda reminded me of the (older) Neptunia games in that regard.
It can be a very beautiful game, though. Some of the dungeon areas look really nice and the character models are pretty good as well. But the school looks rather bland, but it has some really nice lighting. Animation's are rather bad which along with the occasional stutter makes it all feel a bit stiff, but that's more or less common for these kinds of games, especially Gust games. Not like Atelier handles it much better.
The music is good, great even at points. The standard background music is so calm, though, that it's really making you tired. The standard battle music, however, is excellent, and loud enough to wake you up again. There is a bit too much dubstep in this soundtrack and overall the music just isn't used very well in the game with some very weird transitions especially during boss battles, but overall the music is certainly one of the stronger parts of this game.
Some last things, before I get to that thread title. I like how all the skill names are themed to the character, one character has fruit based attack names, the other one has animal based ones. The main character's skill names are all based on ballet (I assume, don't know much about ballet) and in French. Similarly all the bosses' attacks are in German (they even bothered to use umlauts!), though sometimes I get the feeling the translator didn't quite catch what they were going for here, since some of the names make no sense and actual German grammar is non-existent. But overall the translation is surprisingly good and thankfully there are no honorifics here. But there are lots and lots of typos, some really painful ones, and many missing or doubled words. It seems there just wasn't enough budget to check the script properly. And, as usual for Gust, the credits roll is really nice.
So then, let's get to the creepy part. Somehow this game thought it would be fine to downright exploit these girls. Gust has its history with, let's say, sexually themed games. Nights of Azure especially had some rather risky costumes and, well, over-sized proportions. Which I guess, is okay, a bit weird, but properly harmless. At least you don't have to rub anyone or worse.
Blue Reflection has its very own kind of creepiness and it's arguably much much worse than anything Nights of Azure ever did, it's probably more in the tradition of some of the more problematic scenes of the Arland series. The game does its best to make you feel like you're a voyeur stalking around these girls. There are low angle camera shots every time they see a chance, you get to see these (high school) girls when they are changing clothes, when they're in the shower. There are very obviously placed camera shots when they are swimming, you get to watch the main character taking a bath and there are special scenes just so you can watch every character in the rain in their drenched (and see-through) white school uniforms. Look under that NSFW spoiler tag above for a small selection of all this. The game is just full of this kinda of stuff. It's sickening and enough reason to just downright avoid this game. There's worse on the market, even on consoles (and especially, but not only, the Vita), but that's hardly any excuse.
So, either someone on the staff has a severe problem that desperately needs therapy or the Japanese (niche) gaming market is twisted beyond repair by now. Either way, this is not okay.
There's potential for a good sequel here, and from what I've read they are already considering one, but from how these things usually work I doubt they remove or even reduce all the creepy stuff which is a shame, because there is potential in the premise of the series.