Ball Wars ("Ball Wars: Country Ball Battle" on Google Play) is made by DIGCY SARL AU. There is no account. Here is how to remove everything.
Email hello@digcy.com with the subject "Ball Wars data deletion" and the nickname you use in the game. We delete your leaderboard entry (nickname, wins, games played, best streak, random player number) within 30 days and reply to confirm. Nothing is kept afterwards.
Your stats, settings and nickname are stored only in the app on your phone. Uninstall Ball Wars (or clear its storage in Android Settings → Apps → Ball Wars → Storage) to delete them.
Ads are provided by Unity Ads. To limit ad personalisation, choose "No, basic ads only" in Ad settings on the game's home screen, or reset/delete your advertising ID in your phone's settings. Unity's data requests: unity.com/legal/game-player-and-app-user-privacy-policy.
Online rooms send game data live between players and are not stored.