Adding online leaderboards transforms a solitary single-player game into a competitive social experience. Google Firebase is an ideal backend choice for indie game creators because it offers generous free tiers, real-time database synchronization, and seamless Unity SDK support.

1. Adding Firebase to Your Unity Project

Download the official Firebase Unity SDK from the Firebase console. Import the FirebaseAuth.unitypackage and FirebaseDatabase.unitypackage packages into your project. Place your generated google-services.json (for Android) in your Assets/ folder.

2. Seamless Anonymous Authentication

Do not force players to fill out lengthy registration forms before playing your game. Use Firebase Anonymous Auth so every player gets a unique cloud user ID instantly in the background on their very first launch.

3. Saving and Querying Top Scores

Structure your Realtime Database with a clean node path such as scores/{userId} containing username, score, and timestamp. Use Firebase queries (OrderByChild("score").LimitToLast(100)) to display global top 100 rankings efficiently without overloading client bandwidth.