Simon Thomley and his studio Headcannon, who worked on the Retro Engine remakes and Sonic Mania, developed the Origins remaster of Sonic 3 & Knuckles.[1] Thomley said he was contracted to develop the remaster separately from Origins.[15] The compilation marks Sonic 3 & Knuckles' first rerelease since 2011,[16] following speculation that soundtrack licensing problems arising from Michael Jackson's involvement with Sonic 3 were preventing new releases.[4] As Sega was unable to use the soundtrack for Origins, Sonic Team composer Jun Senoue rearranged several tracks originally written for Sonic 3 prior to Jackson's involvement; they were previously featured in the 1997 Sonic & Knuckles Collection for Windows.[17][18]