Brickwave has no account and no sign-up. Your runs, best scores, coins, skins, achievements and Codex are saved on your phone and nowhere else. The name you choose stays on the phone too.
The whole game plays offline: in airplane mode, on the subway, on holiday. The Daily Challenge and the Weekly Mutation are made on the phone from the date.
The network is used for two things: the ads, served by Google AdMob, and the purchase that removes them, through Google Play. In Europe, a consent form asks your choice before any ad. If you refuse, Brickwave requests no ads. Privacy & ad consent, in Settings, lets you change your choice.
The details are in the privacy policy.