Long story short I would like to add unlockable online achievements into my game, I am unsure of how to set it up using my own hosting service and database, and I couldn't find any tutorials on how to do that, but I did stumble upon google play services and I have a couple of questions about it
1) Does the game have to be in the Google Play store as an app to use their services? I don't plan on releasing my game into the app store, It'll be an HTML5 web game, which will be embedded onto my own website. Will I be able to integrate achievements and a leader board that will be work if the game is hosted on my own website?
2) My game is still in development, can I still adding unlockable achievements now or do I have to complete the game and upload it to google?