Leaderboards can be found in the following game modes:

Challenge Leaderboards
The objective of the Challenge Mode is to earn as many points as possible within four rounds by doing high combos, mixing attacks, not getting hit, and completing sub-objectives. Once the four rounds are completed, the game will post your score to an online leaderboard and attribute an overall rank to your score. You can see your score, your friends’ scores, and the overall leaderboards of all the players in the world.

Note: In the Survival Challenge Mode, the total number of rounds completed will be posted in the leaderboard instead of a score.

Arcade Leaderboards
Like the Challenges, progression into an Arcade Level will give you points. Points are earned by attacking or defeating enemies, mixing attacks, and not getting hit. Once all seven levels are completed, your score will be posted on the Arcade leaderboard.