About a couple of years ago I realised that a member known as Kroc Camen was working on a Sonic 1 SMS ROM editing tool. This got me thinking about some ideas, looking at the hacking guide on this site, I was able to construct a crude level editor which allowed me to create Scrap Brain Zone Act 3 from the MD/Gen version and apply it to the SMS version (Seen in this video) However I then thought what if Ancient (the company who developed Sonic 1 SMS/GG version) made a version of Sonic CD for the SMS/GG (although the title wouldn't make much sense unless SEGA created some sort of Master CD/GGCD). Technically there's a huge amount of unused space within the game, and with the way the games art is compressed, it may be possible to create this albeit missing a couple levels. The palette limitations wouldn't really hinder what art could be created either. As a result I was able to create tile sets for the following... Pa = Past, Pr = Present, BF = Bad Future, GF = Good Future Palmtree Panic Pa,Pr,BF,GF Collision Chaos Pa,Pr,BF,GF Tidal Tempest Pa,Pr,BF,GF Quartz Quadrant Pa,Pr,BF,GF Metallic Madness Pa,Pr,BF,GF Title Screen Zone Title Card Capsule Art Sonic Super Peel Out Art Metal Sonic Sprites Amy Sprites Here are some examples of how the art would look in game... Title Screen: Palmtree Panic: Spoiler Collision Chaos: Spoiler Tidal Tempest: Spoiler Quartz Quadrant: Spoiler Metallic Madness: Spoiler In terms of the other levels, I had done a bit of work on Wacky Workbench, my ide would be to use the lightning conductors from Sky Base and re-texture them. Seeing as the springs are tiles in S1 opposed to objects, The springy floor would just be a re-texture of the springs. In terms of music, I tried editing existing music in game but it sounded awfull. ideally I could create some sort of MIDI to S1 SMS format tool to do this. It looks as though the editor that Kroc was working on hasn't been touched in quite a while, which is a shame, I myself had a go at making an application for it, but it wasn't very good as I didn't know enough about the ROM's details. So hopefully if someone manages to continue his work I could potentially finish this project.