If the player enters the sound test mode and sets the toggles to FM NO.46, PCM NO.12, and DA NO.25, the game will cut to a screen depicting a collage of Sonics with bizarre, humanlike faces with the boss theme playing over it. Atop the collage is Japanese text which translates to "Infinite fun. Sega Enterprises. –Mazin Picture", referencing a tagline used by the Sega Sougou series of catalogs. Meanwhile, "Mazin" is the childhood nickname of Masato Nishimura, the game's landscape designer; the moniker can also be romanized "Majin", but Nishimura stated on Twitter that he prefers the "Mazin" spelling. According to Nishimura, this Easter egg was planned to have an additional feature where pressing a button combination would change the text to read "Infinite hatred proceeds from excessive fun," a play on the Japanese aphorism "The greatest hate proceeds from the greatest love." However, after unsuccessfully attempting to enter it in the finished game, he theorized that he either forgot the combination or removed it prior to release.

Following the Easter egg's publicizing online, it became a widespread subject of attention for its apparently disturbing nature due to a mixture of its appearance, the eerie tone of the US version's boss theme, and misinterpretations of the "Majin" spelling of Nishimura's nickname as the homophonous 魔人, meaning "demon." This then morphed into a rumor that the Easter egg was designed as an anti-piracy feature, a claim which Sega repeated on the 2011 remaster's Google Play Store listing. However, Nishimura denied that the screen was intended to scare players.