It is not necessary to provide personal information. However, if you want to take part in the highscore, then we try to get by with as little data as absolutely necessary. The following data is then transferred.
For authentication we use Firebase Authentication.
We use a custom highscore service which stores your unique firebase authentication user id along with your submitted score and the date of your game. This data is stored on servers of all-inkl.com in germany.
To improve the stability of the game, we use Firebase Crashlytics to keep track of bugs.