At the moment, we aren’t recruiting for beta testers for Mini Metro. If we decide to do so in the future, we’ll announce it on our social media and on Reddit! There is an opt-in beta available on Google Play which you can access via navigating to Mini Metro on the Google Play app. We use this to test occasional features on Android and maintain integrity on the leaderboards, but it does not get new game content earlier than other versions of the game.