Earlier quoted context omitted.
I can't see it working well in a game scenario, but the vast majority of CRUD apps out there could be safely implemented using Parse's security model (as described in lacker's link).
They use a game in their JS documentation! And as they wrote it it's totally vulnerable to the user incrementing their own score. It's not just games, either. As soon as a client-server solution gets beyond utterly trivial it becomes hard to see how you'd do it without server logic. Take another example described in lacker's link -- a messageboard post: the ACL defines whether or not a user can make a new post, but w…
You'd probably want to push events into the users profile, have the game ping your server to tell it that there are events waiting, Pull those events on your server and then increment the score. On your server you can have sanity checks and do cheat detection.