How would I get the amount of players in a GAME?

I don't mean in a single server, I mean in an entire game. I already know of a way using Datastores, but I'm afraid it might take in to many requests. Is there the possibility of a httpservice method?

Game > Developer Stats. That will tell you how many players and how many servers.

Hope this helped. If it did, please Upvote it and make it an acceptable answer! Thanks!