Sonic 1 Mixed Beta 1.2 is a ROM hack of Sonic the Hedgehog for Sega Genesis. The "Mixed Beta" suggests a version combining elements from different beta builds or versions of the original game. The version number (1.2) indicates multiple updates. The ROM hacker has likely combined and adjusted assets and gameplay from different stages of Sonic 1's development. The original Sonic the Hedgehog was created by Sonic Team for Sega.

Sonic 1 Mixed Beta 1.2

Sonic 1 KAwarino REV01