What seems to be the problem?
The game doesn't work because of these reasons:
- The game is missing a build/manifest file/s (try redownloading the game)
- The game doesn't load (yes, this game requires internet connection)
- The game doesn't log you in (this might be a problem to the database)
The database has a limitation to desktop builds so it might not even work properly. Maybe using an Android emulator fixes the problem?
You can read this issue for more information about this problem: Issues_with_Firebase_in_Unity_Desktop