Currently, if you update your Galaxy S20 series to Android 11 version and Samsung's ONE UI 3.0 version-which were officially released on December 3rd, you may not access to the game. 
We predict that there is an issue related to the compatibility between the Unity 3D engine and ONE UI 3.0. It may take some time to figure out how to fix it.
Therefore, for who have not yet updated devices, please refrain from updating until the problem is completely corrected.
[Devices Undergoing Inaccessibility Issue]
- Galaxy S20, S20, S20+, and S20 Ultra
[How to turn off automatic updating]
- [Settings] - [Software Updates] - Switch the Auto-Download setting to OFF
We are very sorry for the inconvenience of playing the game. 
We'll do our best to solve the problem as soon as possible.