Sprite comparison for Mania's intro animation (SegaSonic, Sonic 1, 2 and CD) : r/SonicTheHedgehog

Sonic the Hedgehog (1991)/Beta elements, Sonic Wiki Zone

Genesis / 32X / SCD - Sonic the Hedgehog CD (Sega CD) - Sonic the Hedgehog (Special Stage) - The Spriters Resource

Sonic Origins has been listed on PSN in Australia and New Zealand with a new description. : r/SonicTheHedgehog

Sonic The Hedgehog Compilations - Every Sonic Collection Before Sonic Origins

Proto:Sonic the Hedgehog (Genesis) - The Cutting Room Floor

Which Sonic Sprite Is Best?

I edited “classic sonic” from generations to look more like the actual classic sonic : r/SonicTheHedgehog

Sonic Mania studio confirms they are working on Origins Plus

Best Sonic Games Of All Time

Why is it difficult and rare for Sega to make a good modern Sonic game? - Quora

Sonic Origins Contributor Shares Frustrations Over The State Of The Game