Sonic Heroes features several unlockable elements that extend the game's replayability and reward dedicated players. Knowing how to unlock these can provide additional challenges and fun.
- Team Campaigns: Initially, only Team Sonic is available. Completing Team Sonic's story unlocks Team Dark. Completing Team Dark's story unlocks Team Rose. Completing Team Rose's story unlocks Team Chaotix.
- Last Story: To unlock the 'Last Story' (the true ending), you must complete all four team campaigns and collect all seven Chaos Emeralds with at least one team. This will then unlock the final boss battle against Metal Overlord.
- Challenge Mode: Completing any team's story campaign will unlock Challenge Mode for that specific team.
- Battle Mode: Completing any team's story campaign will unlock Battle Mode.
- Super Hard Mode: Completing the Last Story will unlock Super Hard Mode, which significantly increases the difficulty of all stages.
- Sound Test: Collecting all 140 Emblems (achieved by getting an 'A' rank on every stage for every team, and completing all Challenge Mode missions) will unlock the Sound Test option in the main menu.
The path to 100% completion is long but rewarding, offering a true test of your Sonic Heroes skills.