It's possible to play the game using an Atari 2600 controller, as every button besides start works as a jump button, and thus the game is fully playable despite the controller only having a single button.

The title screens of Sonic the Hedgehog and Sonic the Hedgehog 2, with Sonic (a character known for his super speed) posing and waving his gloved hand inside of a ring lined with stars and a ribbon banner at the bottom, could possibly be taken from the logo of the 1981 anime adaptation of the Akira Toriyama manga "Dr. Slump" and its speedy protagonist Arale. It should also be noted that the ring surrounding Sonic has giant wings protruding from its sides, which appear to reference the angel wings on Arale's cap that also feature in the intros to the anime and some of the Dr. Slump films.

While it's not known if any Sega employees have commented on this connection, it was acknowledged in the form of a small cameo appearance where Sonic gets outrun by Arale in the 1993 sequel manga "The Brief Return of Dr. Slump".

Sonic was originally planned to have a human girlfriend called Madonna, whose design was directly based on the sexually provocative American pop singer of the same name. In line with this, character designer Naoto Ohshima designed Madonna to be attractive and to chase Sonic around (similar to how Amy Rose acts in later games), which he described as a "male fantasy". Aside from concept art, Madonna's only known appearance was in a 1990 tech demo for the TeraDrive, a Japan-exclusive IBM PC with a Sega Mega Drive integrated into it. There are two separate claims as to why Madonna was removed. Programmer Yuji Naka originally claimed in 1993 that Madonna's planned role was to be a damsel-in-distress, with Sonic needing to save her, and that she was ultimately dropped because the team wanted to move the series in a different, more orthodox direction to set it apart from Mario. However in 2009, Sega of America product manager Madeline Schroeder claimed to be the one who removed her as part of an overall effort to "soften" Sonic's image for younger audiences and foreign countries under the belief that Madonna was too Japan-esque. In 2015, Madonna would be reimagined by comic book writer Ian Flynn and appear in Archie Comics' Sonic the Hedgehog comic book series, having been redesigned to be an agent of G.U.N.'s C.L.I.P. division named "Madonna Garnet".

The appearance of Longclaw in Paramount’s Sonic the Hedgehog films is reminiscent of the tiles that resemble an owl's head in the Labyrinth Zone from the original Sonic the Hedgehog. In fact, the first film's opening scene features the tile design engraved on a rock as an Easter egg, further hinting at the connection.