Game Maker Studio Tutorial - Make your first Android Game #2 : Google Play Service

First of all, I assume that you already have a Google Play Developer Account

If not, visit https://play.google.com/apps/publish/signup/ to register an account.

The one-time fee is $25. It takes about 2-3 business day to finish the registration process

Once complete, now you’re into the Google Play Dev Console.

So in this tutorial, I'll show you how to upload the APK file and set up Google Play Services.

Upload APK file to Google Play

1.    Add new Application

Navigate to the first tab on the left side, you can see this button "Add new application". Click it.

A popup appears. Add the title of your game and the default language.

Then, choose “Upload an APK” to continue.

Add new Application

Upload APK file

2.    Upload APK file to Beta channel

I don’t know much about the difference between Alpha or Beta channel, but since you’re in the testing phase, you should upload the APK file to either channel ( not the Production channel )

In this case, I choose the Beta Channel.

Select and upload your APK file.

Once it’s ready, now go to the next step.

Upload to Beta Channel

Until now, if you don't want to use Google Play Services for your game, you can start testing and ignore the latter steps.

If not, please continue.

3.    Set up the Google Play Service

Please remember, the Google Play Service is not a game, it just the supporting service for your game’s social features, for example : Leaderboard, achievement.

Again, if you don’t want to have these features, then just ignore this step.

• Navigate to the second tab which has the gamepad icon

• Click “Add a new game”

• Choose “ I don’t use any APIs in my game yet”

• Add the name of your game, choose it category, then click “Continue”

Add Game Service

4.   Inside the Google Play Service window

There’re six steps to be done before publishing any Google Play Service.

See the string next to the game’s name ? It’s the App ID, copy it for later use.

Inside Google Play Service & Application ID

• Game details : similar to the “Product Listing” tab , you can copy and paste the details

• Linked App : this is where we can integrate Google Play Service in the game.

• Achievements and Leaderboards : these are features of the Google Play Service, I’ll show you how to add the Leaderboard, the achievement is pretty much the same

• Testing : where you can add the testers of the game

• Publish : once all of these steps are completed, it’s ready to publish the service.

Important note

In order to test the features of Google Play Services, the testing account MUST have a Google+ ( Google Plus ) account available. You can register one at plus.google.com

5.    Link the app

OK, now you go to the second step ( Linked app )

• Choose the “Android” option, you will see another window.

• Add the name of your game

• Choose the package name : just click the field and you will see your previous uploaded APK, click to choose it.

• Disable the Anti privacy : if it’s enabled, you’ll have errors testing your game.

• Once done, click “Save and Continue”

Linked App

Linked App Details

You’ll be shown to next step : Authorized your App

Authorize your App

Click this button, there’s popup that requires you to fill in some info. If you don’t have enough resource ( like product logo or homepage ), just ignore them and click “Continue”

OK, now you have to give the SHA1 key

Fill the SHA1 key

• Come back to GMS-Preferences –Android

• Navigate to Keystore file, click the Show Key Hash.

• Copy the string in Key Hash ( SHA 1 ) and paste it to Google .

• Once done, click “Create Client”, wait a bit.

Congratulations ! You’ve linked your app.

6.    Add the Leaderboard

So, in order to add the leaderboard, go to the fourth part “ Leaderboard”

Add Leaderboard

• Click to add the leaderboard, you’ll see another window

• First, supply the name of this leaderboard, this name will be shown to players. You can call it “Highscore”, “Top ten”,etc …

• Second is the score formatting, normally we choose Numeric, with no decimal value.

• If you supply no icon, then it will use Google default icon for this

• Ordering : “Larger is better” : the larger value will stay at the top, while “Smaller is better” has reversed effect.

• The rest is left default.

• Once done, click “Save”, you can see a string next to the Leaderboard’s name, copy it for later use.

7.    Integrate the Leaderboard in our game

• Go back to GMS, navigate to Global Game Settings-Android-Social tab

• Choose “Enable Google Services”, add the App ID ( next to the game name ) to the box.

OK, it’s done.

8.    Connect to Leaderboard

Now all things are set up, we just need to add some code. It's easy.

Now, go to your GMS.

Put an object in the very first room ( usually the room for Menu ). This object uses no sprite.

Go to Add Event -> Other -> Game Start

Go to Control tab ( in the right ) and pick the “Use some code “

Insert the following code

if os_is_network_connected()
{
    if (!achievement_login_status())
    {
        achievement_login()
    }
}   

This code will log you into the Google Play Service

Traditionally, in the game, you will have two buttons. Use these codes, they will be executed when you press the button

Show Leaderboard button

if achievement_available()
               {
                achievement_show_leaderboards();
}

Submit score to Leaderboard

if achievement_available()
               {
achievement_post_score("xxx", score);
}

• “xxx” is the string next to the Leaderboard, remember to include the “” because it’s a string.
• Score is the var which holds the scoring value in your game.

This is the very basic steps, in my game however, I gather all of the code into one button.

The code is as follow

if os_is_network_connected()
        {
            if (!achievement_login_status())
                {
            achievement_login()
                }
             if achievement_available()
               {
                achievement_show_leaderboards();
                achievement_post_score("xxx", score);
               }
        } 

Note
Google doesn’t allow you to publish your game unless you provide at least 5 achievements.

If your game doesn’t have any achivement, you could add 5 achievements in the game.

Remember to choose the “Hidden” option in “Initial state” so the achievement doesn’t show up in your game.