In the opening cutscene, a sprite of Tails running can be found in the VRAM. However, when Tails is eventually revealed, he's walking, not running. Could it be possible that he was meant to run along with Sonic rather than walk after him when he goes off-screen?
- When accessing the Sound Test feature, the song 099H can be heard. This is the intro screen music for the Sega Master System version and the title screen music for the Game Gear version of Sonic 2.
- When accessing the Sound Test feature in the Game Gear version, the song titled "BGM#09BH" can be heard, but was not used in the game. The track was later used in Sonic Triple Trouble as the Sunset Park Act 3 song.
In the Sound Test screen, Sonic can shoot a fireball by pressing , then or .