Not tested on other flash-cartridges, but it should work everywhere, I think. At last, heres the last Sonic 1 level, the Scrap Brain Zone This also includes the Final Zone boss as well. Hack is working on hardware! Tested on Sega Genesis VA6.5 with Mega Everdrive Pro.

Also you can use Air Roll (press A/B/C in the air, while you are not jumping/rolling). Master it and you can reach some heights on multiple paths. A lot of things in level design based on momentum basis.

Gameplay also as Sonic 1, without spindash, so only thing you can use here is momentum. Plot of hack is basically same as Sonic 1, it's just variation of 'What if, events happened on another island?'. Sonic The Hedgehog: Ancient Isles (formerly known as 'Catswell's Edition') - is a hack that directed to create simple, chill yet fun and memorable experience with a whole bunch of absolutely new levels with drawn from scratch sprites.

Aren't you tired of these hacks overwhelmed with new features that make you surprised every time? Are you want to just chill out in some simple atmosphere with new levels? Well, here you are!

Sonic the hedgehog 1 scrap brain zone