Posted by Todd Kerpelman, Developer Advocate

Saved Games Are the Future!

I think most of us have at least one or two games we play obsessively. Me? I'm a Sky Force 2014 guy. But maybe you're into matching colorful objects, battling monsters, or helping avians with their rage management issues. Either way, there's probably some game where you've spent hours upon hours upgrading your squad, reaching higher and higher levels, or unlocking every piece of bonus content in the game.

Now imagine losing all of that progress when you decide to get a new phone. Or reinstall your game. Yikes!

That's why, when Google Play Games launched, one of the very first features we included was the ability for users to save their game to the cloud using a service called the AppState API. For developers who didn't need an entire server-based infrastructure to run their game, but didn't want to lose players when they upgraded their devices, this feature was a real life-saver.

But many developers wanted even more. With AppState, you were limited to 4 slots of 256k of data each, and for some games, this just wasn't enough. So this past year at Google I/O, we launched an entirely new Saved Games feature, powered by Google Drive. This gave you huge amounts of space (up to 3MB per saved game with unlimited save slots), the ability to save a screenshot and metadata with your saved games, and some nice features like showing your player's saved games directly in the Google Play app.

...But AppState is Yesterday's News

Since the introduction of Saved Games, we've seen enough titles happily using the service and heard enough positive feedback from developers that we're convinced that Saved Games is the better offering and the way to go in the future. With that in mind, we've decided to start deprecating the old cloud save system using AppState and are encouraging everybody who's still using it to switch over to the new Saved Games feature (referred to in our libraries as "Snapshots").

What does this mean for you as a game developer?

If you haven't yet added Saved Games to your game, now would be the perfect time! The holidays are coming up and your players are going to start getting new devices over the next couple of months. Wouldn't it be great if they could take your game's progress with them? Unless, I guess, "not retaining users" is part of your business plan.

If you're already using the new Saved Games / Snapshot system, put your feet up and relax. None of these changes affect you. Okay, now put your feet down, and get back to work. You probably have a seasonal update to work on, don't you?

If you're using the old AppState system, you should start migrating your player's data over to the new Saved Games service. Luckily, it's easy to include both systems in the same game, so you should be able to migrate your users' data with their ever knowing. The process would probably work a little something like this:

Enable the new Saved Game service for your game by Adding the Drive.SCOPE_APPFOLDER scope to your list of scopes in your GoogleApiClient. Turning on Saved Games for your game in the Google Play Developer Console.

Next, when your app tries to load the user's saved game First see if any saved game exists using the new Saved Games service. If there is, go ahead and use it. Otherwise, grab their saved game from the AppState service.

When you save the user's game back to the cloud, save it using the new Saved Games service.

And that should be it! The next time your user loads up your game, it will find their saved data in the new Saved Games service, and they'll be all set.

We've built a sample app that demonstrates how to perform these steps in your application, so we encourage you to check it out.

In a few months, we will be modifying the old AppState service to be read-only. You'll still be able to read your user's old cloud save games and transfer them to the new Saved Games service, but you'll no longer be able to save games using the old service. We are evaluating early Q2 of 2015 to make this change, which should give you enough time to push your "start using Saved Games" update to the world.

If you want to find out more about Saved Games and how they work, feel free to review our documentation, our sample applications, or our Game On! videos. And we look forward to many more hours of gaming, no matter how many times we switch devices.