Blue Archive shines in so many ways. Some are noticed early, like an incredibly amazing soundtrack(maybe you can check it before trying) or the lovely characters, but others take time. Its similar to priconne in character development or gacha mechanics. The main story is amazing, it will make you laugh and cry with well built characters that face different and unexpected plots. Gameplay wise, it may seem simple at first, you can auto stages (and even sweep as many as you want just using your stamina). However, due to the 3 different damage and armor types, the 3 different terrains and the mechanics of bosses and raids, there are many details to take into account when trying to overcome harder challenges. Gacha and banners system is similar to priconne, with a spark system after 200 pulls to exchange the rate up character. Nexon has been very generous and a f2p player can easily reach a spark to guarantee the rate up character in 2/2.5 months.
There are things thst could improve, like some characters lacking a l2d lobby screen, and it would be amazing if it were fully voiced(it's not) There was also a censorship drama, but it was just 1 picture in the story and it never happened again, pretty small stuff. Overall it is an awesome game that will grow on you.