@rulitawyn we understand your concerns regarding the game but I would like to point the fact that any add-on is potentially able to harvest a lots of data.

Opera has automatic and manual reviews of the code uploaded on the add-ons, checking for problems of privacy and security. At the moment Dedalium has passed all the audits and is trusted by all the major browsers. In Dedalium we need to trigger actions on the pages you visit but on no occasion we store which page you visited, we encode the url of the page and we check the action in there with an also encoded reference on our database so we can show you the appropiate content on any page without storing your browser history. The only data stored is the game objects collected.