SEGA rushed the production time to meet up with a Christmas release and for Sonic's 15th Anniversary.
A day and night feature was planned and present in early builds shown off at Tokyo Game Show 2005 and E3 2006 but the concept was ultimately cut from the final game due to time constraints. The idea would be revived later for Sonic Unleashed (2008).
Silver's Theme Song "Dreams of an Absolution" is an unintentional remix of Green Hill Zone's theme music. The song writer said he didn't realize he had mixed the music into the song.
A port for the PC was announced but never released.
In 2010, Sega delisted Sonic 2006 as a downloadable title from the Xbox Live Marketplace because they felt the game was harming the Sonic brand by being available for purchase.