WARNING: MINOR SPOILERS AHEAD!
So I was playing Brawl, and I unlocked Luigi. W00t! Then I unlocked Luigi's mansion. I looked at the "My music" settings for Luigi's Mansion and saw the "Tetris A theme" as a song! "WOAH! THAT IS EFFING AWESOME!" I thought, being a Tetris addict. I listened to the song and then realized it. Tetris A theme was a Russian Communist Anthem!
Now all we need is Joeseph Stalin as a playable character, or at least an assist trophy. He could sic the Red Army on all the players!