so, initial impression.
Gameplay - You deploy your team within a certain cost that will recover after each wave and they auto-battle. In other word, simple and par for the course like many other gachas.
Sound and Graphics - good enough. The game is KR voiced instead of JP so I can't really comment on that.
Gacha - by far the aspect with the worst implementation of this game, if not all gachas in general.
You can reroll the beginner banner up to 10 times, HOWEVER, each reroll DOES NOT guarantee you a five star and worse, it is possible to get a whole reroll with nothing but three star. Meaning unless you lucked out and got all your desired five and four stars within 10 rerollst then you're gonna have to hard-reroll your account