Its has cute characters and an interesting Story line, but there still some bugs here and there where mechanic causes fast pace battle to be buggy and annoying.
Then there is the gacha, as like any Gacha their promise of High Rate of getting new characters are as real as God will save you in your dire moments......
My Advice, Dun even bother with Buying any Game Currency as their gacha is as random and Pointless as throwing stone into the sea and hoping for Mermaid to bring you a treasure.