This is a Japanese version of the Sonic CD Plus Plus ROM hack. It likely features similar enhancements to the original release but may include language-specific changes and potentially altered assets to cater to a Japanese audience. The game's origins trace back to the Sega Mega-CD, and it maintains the core gameplay and level designs of the original title while adding community-driven modifications for improved visuals, soundtrack, and mechanics.

Sonic CD Plus Plus (JP version)

Sonic CD (Japan)