There is anti-piracy protection within the Dreamcast version of the game. If the console detects that the game is running from a copied disc and not an official GD-ROM, Eggman will be locked in death cycle at the start of his section in Cannon's Core. He'll immediately start falling through the floor, dying and respawning in the same position repeatedly. It's still possible to reach the end of the level, but visual glitches and a fixed improper camera angle will hinder the player's attempts to navigate the level.
Contributed by ShyanVixen