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Top: Lulu is a character introduced to the WarioWare series in WarioWare: Gold, and who became a fully playable member of the cast in WarioWare: Get It Together. She is seen using a balloon to float around in her character trailer.

Bottom: Lulu's design is actually based on the protagonist of a Japan-exclusive Game Boy Color remake of Balloon Kid (originally for the Game Boy), called "Balloon Fight GB". The girl from that game has an identical outfit and similar hairstyle and bow to Lulu. While this might not be an obscure reference to Japanese players, as the game was never released internationally, most players of WarioWare would be unable to recognize that Lulu's design is a reference.

A panel of a 2008 issue of the Image Comics comic series "Invincible" contains a reference to Francis, the Chapter 3 boss from Super Paper Mario (shown on the shirt of the man near the right edge of the panel), as well as his catchprase, "Hi-technicaaaal!"

Production artwork from the Super Mario World cartoon.

At first I didn't realise that the rating was for the entire GBA Nintendo Switch Online app, and so I was sitting there wracking my brain trying to figure out what on earth could count as sexualised imagery in these games 😆

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