Graphics: I love the chara design which are beautiful and elegant, chibi is also adorable. So many white/gray/silver haired girls, very satisfying.
Sound: Music fits the theme well. Dub is in Korean language, something fresh for my ears.
Gameplay: There is tiles and lanes deployment strategy with wave battle system, but it is simple. You can't deploy all of the units you have because there's cost limitation. It has wipeout stamina/key, but you must do one battle at least.
Story: Journey with the crystal girls to beat dreamless mobs and the dominions. Charas are based on the fairy tales.
Value: Dunno, pity is until 100x summon but will be reset for every banner change. There're another shard currency things for gacha beside gem. Always check shop at resources and marketplace section. You can unlock every skins from charas you have by collecting guild points everyday.