This is a warning to all potential customers. The developers have admitted to having spyware in their product over on Steam (steamcommunity(dot)com/app/782140/discussions/0/1746770563030003703/). The lack of a method of opting out of the data collection (and the fact that the data mining is hidden from the customer) appears to be in violation of the EU's GDPR (General Data Protection Regulation).

Below is the relevant passage from Re-legion's EULA as found on GOG on 3/2/2020.

5. CONSENT OF USE OF DATA
You agree that Ice Code Games may anonymously collect and use information gathered in any manner as part of the product support services provided to you, if any, related to Re-Legion. Ice Code Games may also use this information to provide notices to you which may be of use or interest to you.

The information gathered by Ice Code Games may also include:

-in-game data of the users (start time of a mission, completion of the mission, saves, highscores, progress, progress history, items, etc.);

-demographic data of the users (by Google Analytics implemented into Re-Legion).

-session numbers with a timestamp and the detailed session process (e.g., the User entered this level, the User lost this level, the User entered this screen, etc.);

-your unique device ID;

-location-related information (country, time zone, etc.);

-your device model and device properties (GPU, resolution, etc.).