Hello pedro and welcome to TASVideos. The Sonic series is a fairly technical one, something that I question here by you as there is some things still possible to shave. But... what is the purpose of this ROMHack? There's no information that's been provided about this ROMHack and to me it's a mix mash of Sonic 1 elements from Sonic 2 plus a few extras. The only other thing is that this ROMHack is now a apparently 3 year old demo, but because of how hard it's to find information about this ROMHack let alone the devs themselves about any progress. Also in regards to the title the only two videos I found online referred to the hack as "Extended" whilst another "Extension". I'm lost. Abstained.