Retro Sonic in Sonic Racing: CrossWorlds is typically described as a mod, not a standard unlockable character, so you usually don’t get him through normal in-game progression. The common route people mention is installing the Retro Sonic mod or using a fan-made unlock method, depending on the version you’re playing.

What the public guides suggest

  • One recent mod page says Retro Sonic is added as a replacement for the game’s “Classic Sonic” and is distributed as a mod.
  • Other unlock guides for the game focus on official secret characters like Super Sonic, which is unlocked by defeating all 23 rivals in Grand Prix mode.
  • That means “Retro Sonic” and “Super Sonic” are likely being mixed together in some discussions, but they are not the same unlock path.

Practical takeaway

If you want Retro Sonic specifically, the likely steps are:

  1. Check whether you mean the modded Retro Sonic version or an official character unlock.
  2. If it’s the mod, follow the mod page’s install instructions for your platform.
  1. If you actually meant Super Sonic , beat all 23 rivals in Grand Prix mode to unlock him after credits.

Forum-style read

“Retro Sonic” seems to be a community add-on, while the game’s real secret character unlock is Super Sonic through rival clears.

Availability note

As of the public pages surfaced here, I did not find a standard base-game unlock for Retro Sonic itself, only mod-related references.