Having worked on my first app that implements GameCenter, I had a lot of questions about the process. The main question was how do I implement GameCenter into my app? Do I need to pick the right application template when creating my Xcode project? Do I need to use SpriteKit? Etc
The good news is that GameCenter can be added on after the rest of your application is ready. You should focus on your game mechanics, game engine, user friendliness, etc. After you are satisfied with the core experience, you can add GameCenter (leaderboard, achievements, and other features) afterwards. You can choose any application template and you don’t have to use SpriteKit.
In my app, I had both a phone app & a watch app. You will need to implement GameCenter using Apple’s GameKit Framework. GameKit is currently only for the iPhone, so GameCenter logic needs to be called in the Phone app.
I found great Apple documentation with the same advice:
Here’s a reasonable process to follow when designing a game that supports Game Center:
- Decide which Game Center features you plan to support.
- Define your game mechanics, keeping in mind the requirements and limitations of Game Center.
- Implement your game engine, ignoring Game Center for now. Focus on developing the other aspects of your game, such as your game engine and gameplay. You do this to avoid needing to create an iTunes Connect record earlier than you need to.
- [implement Game Center]
As with any app, focus on nailing the key user experience. Then worry about implementing/integrating GameCenter in your app.