Hi! First i'm sorry for my bad english. So, really first, this tutorial work with the Sonic 1 Hivebrain 2005 disassembly. (i don't test the github version and other). You need to have: _A clean Sonic 1 rom _A clean disassembly (hivebrain 2005 for exemple) _Your disassembly of your hack _Esrael Sonic Editor II You have to open the clean Sonic 1 rom with the Esrael Sonic Editor II. In "Tools", you have the level order editor. Edit the level order as you want, and then, save. Close the ESEII and copy/paste your clean Sonic 1 rom (edited on ESEII) into the clean disassembly folder. Rename the rom to "s1", and split. Make a copy/backup or delete your lvl_ord.bin in your misc folder, of your hack, and copy/paste the lvl_ord.bin of the clean disassembly to your hack. Build and test, and... YES, you have a custom level order! This is my first tutorial. I hope that it will help someone here. Thank you!