In the Boxing Ring stage of the Wii U version of the game, character aliases appear on the screen in the background which reference other games or early concepts, such as Mario's being "Mr. Video Game Himself" referencing his early name "Mr. Video", and R.O.B.'s being Spoiler:"The Last of His Kind", referencing the events of Subspace Emissary from Super Smash Bros. Brawl in which Spoiler:the other R.O.B.s were destroyed.
Contributed by JelloBoyInc
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