An object representing a challenge based on a score in a leaderboard.
- iOS 6.0+
- macOS 10.8+
- tvOS 9.0+
To complete the challenge, the player must score an equal or better score than the score used to create the challenge. When a player beats a score challenge, a new score challenge is automatically issued to the player that issued the challenge unless there is already a pending score challenge that requires a better score.