This may be discussed before (I found nothing with searching) but I was debugging my hack, Sonic 2 long version, when I tried to fix the Death Egg zone 3 act number. Remember, the 3 was going from the right instead of the left because I added a yellow character at the end of the string "DEATH EGG". Now, I have found how to change act numbers at the start and the end of a level! So, my 3 under DEZ is going from the left like in Metropolis 3! Level startup numbers (splash screen): $13DF2-13E08 Here are listed all levels that displays nothing instead of the act number. They are listed like this: 0C 00 00 XX 67 SS XX is your level. Jump SS bytes if the level XX is loaded to display nothing (go to $13E3E usually). Already listed: Sky Chase zone, Wing Fortress zone and Death Egg zone. $13E08-13E14 You can find here another list of levels. These levels will display a 3 instead of a 1 or a 2 character. 0C 00 00 XX 67 SS XX is your level. Jump SS bytes if the level XX is loaded to display a 3 instead of 1 or 2. Metropolis zone has not a 67 SS because the next bytes are that will load a 3. So, SS usually will go to $13E14 if you add others levels to the list. Already listed: Metropolis zone (level 05). End of levels (SONIC GOT THROUGH...): $14148-1415C List of levels that display ZONE string instead of ACT. Same system as before. Already listed: SCZ, WFZ and DEZ. $14168-14184 List of levels that display nothing instead of the act number. Already listed: SCZ, WFZ and DEZ. $14184-1418A List of levels that display a 3 instead of 1 or 2. Already listed: Metropolis zone. EDIT: when a level will displays nothing or a 3 instead of 1 or 2, ZONE instead of ACT, both acts 1 and 2 will be affected. I hope this will be useful for some people.