Google Play Games Services
GPG not only allows common game features like Achievement and Social Leaderboard, it also provides apis for building Multiplayer(Turn-based or Realtime) games. GPG also provides a dashboard-
- Events – GPG allows for adding events to be logged by clients.
- Achievements and Leaderboards – Create achievements with images and manage multiple leaderboards.
- Saved Games -GPG allows saving game state to be saved on google cloud. This allows players to take up the game on another device without starting over from start.
General Comments – Though I found GPG to be much more simplistic, it has its own sets of shortcomings like tight integration with Google+. There are ways to make GPG interact with facebook but they are messy. Also the Unity client for GPG only allows exporting to Android or iOS. Even web player is not supported.