For this achievement you'll have needed to unlock all other achievements in the game.
For this to happen you'll have needed to do the following:
-Complete Arcade Mode with all characters w/ one undefeated run
-Lose to Galactus with a Game Over
-Complete Arcade Mode on Hard
-Complete 320 Missions across all characters
-Reach 100,000 Player points
-Land an Uncanny combo (91+ Hits)
-Assemble specific character teams
-Arrange specific character face-offs
-Reach Fighter Rank Online (5 win streak)
-Perform specific advanced maneuvers
-Misc and numbered type achievements
After all of these have been performed you'll net this final achievement for 1000G in the game! Good Luck!