I was going to recommend Ship of Harkinian as a reverse engineered Ocarina of Time but they don’t have a license file posted in their git repo so not technically open source unless I’m just missing it. It uses libultraship which is mit licensed.
Edit: Looks like they started by forking another unlicensed project so until that project chooses a license they don’t want to choose a license for themselves. What a mess.
If reverse-engineered Nintendo games count, then Super Mario 64 and Pokemon Emerald whose engine is technically open source.
EDIT: Minecraft Beta 1.7.3 has been reverse engineered multiple times too.
I was going to recommend Ship of Harkinian as a reverse engineered Ocarina of Time but they don’t have a license file posted in their git repo so not technically open source unless I’m just missing it. It uses libultraship which is mit licensed.
Edit: Looks like they started by forking another unlicensed project so until that project chooses a license they don’t want to choose a license for themselves. What a mess.