Glad you enjoyed my interpretation of the limitation!
The Leaderboard was implemented using Unity Gaming Services. It basically involves:
- Setting up a Unity Account
- Creating a Leaderboard on their Gaming Services website through a Dashboard (simple step-by-step process)
- Download the Leaderboard package inside your Unity Project
- Linking the leaderboard to a Unity Project (Should have an option at project creation to connect to Unity Cloud, makes this easier)
- Writing some code to handle basic functionality and display the leaderboard (couple dozen lines of code)
Hope this helps!