I think the issue is probably that your using your package identifier for your game id. Game id is badly named, most of the time it will be the same as your application id. It should look like 12345678987. This will be preventing you from logging in, and the other methods will fail if your are not logged in.
I've changed the name of it for the next release to "Application ID (android)" which will hopefully make it a little more obvious for people.
Thank you so much for this, now the automatic login seems to work. However the leaderboard is still not working. I tried to debug it a bit and I have 2 Text fields that should tell me if the submission and retrieval of score works. This is the code that I added:
(Google Play) On score submit success -> (CheckLeaderboard) Set text to "Check Leaderboard: 1"
(Google Play) On score submit fail -> (CheckLeaderboard) Set text to "Check Leaderboard: 0"
(Google Play) On hi-score request success -> (CheckReceived) Set text to "Check Received: 1"
(Google Play) On hi-score request fail -> (CheckReceived) Set text to "Check Received: 0"
If my understanding of the Google Play object is correct, I should get a 1 if the score is sent to the leaderboard and if I receive it back when I click the button to do so (right?). I re-uploaded the game on Google Play with all these modifications, and when I click the button to submit the score or retrieve a hi-score, it actually puts a 1 in my text boxes, which I guess it means it is working. However, nothing shows inside the game (I expected to see an actual leaderboard list, with all the scores I submitted, in order). Also when I check the leaderboard in my Google Play console I can't find any score there. Do you know why this might be the case and how can I fix it? Thank you!