SonicGenesis89 shed some light on some developmental do-dads for Sonic CD in the Supreme Topic of Other Knowledge. Also these: http://info.sonicretro.org/File:Sonic_CD_Palmtree_Panic_Proto_Present_02.jpg http://info.sonicretro.org/File:Sonic_CD_Palmtree_Panic_Proto_Present_04.jpg http://info.sonicretro.org/File:Sonic_CD_Palmtree_Panic_Proto_Present_05.jpg http://info.sonicretro.org/File:Sonic_CD_Palmtree_Panic_Proto_Present_06.jpg plus http://info.sonicretro.org/File:Sonic_CD_Collision_Chaos_Proto_Bad_Future.jpg So you know how this community has been dissecting blurry screenshots for 20 years? Turns out nobody noticed this extremely early build of Sonic CD. The one where Palmtree Panic present has an entirely different background (more similar to the future version). Things of note: - Simpler background (which actually lines up better with the Past/Future versions) - Present trees use the same graphics as the bad future ones from the 510 prototype - Minor layout differences I did some digging and have found magazine coverage - it all stems from the first couple of months of 1993, usually post-Winter CES. Screenshots also often match which suggests they came straight from Sega too. http://retrocdn.net/index.php?title=File:EGM_US_044.pdf&page=120 - EGM (US) http://retrocdn.net/index.php?title=File:MegaForce_FR_14.pdf&page=28 - Mega Force (France) http://retrocdn.net/index.php?title=File%3AConsolesPlus_FR_018.pdf&page=12 - Consoles+ (France) http://retrocdn.net/index.php?title=File:Megazone_AU_28.pdf&page=16 - Megazone (Australia) http://retrocdn.net/index.php?title=File%3AVideoGames_DE_1993-03.pdf&page=26 - Video Games (Germany) I spy a different time warp transition. My best guess is that this was a really early demo (think Nick Arcade Sonic 2), probably with only one playable level without cheats or hacking, not much time travel, but an animated intro to gawk at. I would assume at this stage that Palmtree Panic's background was changed so they could simulate that giant loop at the start, but that's speculation of course. It's actually quite surprising that this build was even shown off - we're talking January/February 1993, just a couple of months after Sonic 2's launch, while the other Sonic games set for release around Christmas 1993 weren't announced until Summer CES-ish - June. There's also a long period of silence before the 510 beta turns up in the press.