Is it meaningful and legal to use Google Play Services for non-gaming apps?

Is it meaningful and legal to use Google Play Game Services for anything other than a game?

I think that an app that can upload images might have ratings (weekly reviews) and achievements. Or, a language learning app can also use these features to make the learning experience more fun.

Why are there no apps using these features? Is not allowed? Or is the problem that the app will show up as a game in the Play Store even if it's not a game? Will Google ban such apps?