Nothing is sent, and the build cannot send it
Trollvakt asks you to register nothing, keeps no profile of you, posts no scores to any server, carries no advertising, measures nothing and runs no mailing list. Underneath all of those absences lies one that makes them checkable instead of merely stated: the published package declares no internet permission. Android will not open a connection for an application that has not asked for one, so the question of what this game transmits has a mechanical answer rather than a reassuring one.
Your defences, your stars and your furthest wave are written into the storage area Android sets aside for this app alone. They stay on the handset. Nowhere does a copy of them exist in our hands, which means there is nothing of yours here to guard, mislay, sell or be compelled to produce.
Eleven posts are nailed up below, and the war table above lists them. Together they answer what the General Data Protection Regulation requires a notice like this to answer; the eleventh says where to take a disagreement.