Sonic Mania is a love letter to classic Sonic games, filled with numerous easter eggs and references for long-time fans. Keep an eye out for:

- Classic Badniks: Many enemies are updated versions of badniks from previous games.
- Zone Remixes: The remixed classic zones feature elements from other Sonic games. For example, Chemical Plant Act 2's boss is a reference to Dr. Robotnik's Mean Bean Machine.
- Hidden Messages: Some areas might contain subtle nods or messages.
- Soundtrack References: The music often incorporates motifs from older Sonic tracks.
- Debug Mode Secrets: Activating Debug Mode (an unlockable extra) allows you to place objects, including some humorous or unexpected ones.
Exploring every nook and cranny can reveal these delightful homages.