MultiVersus

This is a super straightforward achievement, although keep in mind this can NOT be obtained in custom games with your friends. All you need to do is load up the game, do the tutorial, and then hit the X button to play. It will ask if you want to play solo or 2v2. Select either (or both), complete the match (win or lose), and ta da! 15GS is yours! Happy hunting!

Search for an online game [Before the servers close!]
and play the game in it's entirety