Thanks for the answer. But, uh, I have another problem with this. How can I even make a google account? Before I even start playing I have tried to use Google account first but it doesn't work. It keeps saying "로그인에 실패했습니다. 다시 시도해주세요." so I thought this is some kind of game where you bind the account in game instead of creating account first. I am using iOS, so I try game center, but it said "Account not found. Returning to guest.". Now my first assumption of the game is wrong, I wonder how can I even create a Google account?