This probably seems like an obvious question with an obvious answer, but after seeing the Sonic 1 prototype still having collision issues, I have to wonder, did the TTS demo have any ball/momentum physics or was it just a simple sidescrolling platformer demo? I know a lot of Sonic 1 level art concept makes it clear about the physics, with loops etc., but do we have a time frame on when that art was done? Was it done prior to the TTS demo, and it was just a case of them working hard to eventually implement it? Because I seem to recall that Yuji Naka had already created a sort of momentum engine before they'd even settled on a Hedgehog, but with the S1 protos collision issues, I have to wonder how similar that initial engine was to what we got in the end. Was the initial momentum engine entirely separate from the platforming engine at some point, with the collision issues arising from jamming a platformer engine and a rolling ball engine together? We don't see any loops or meaningful slopes in the TTS screenshots, do we? Is it possible that it was essentially just a sidescroller platformer demo for marketing purposes without the Sonic physics at this stage? Given the appearance of the alternate non-ball jumping sprite, it's similarity with Mario's jump pose, and a creature that for all intents and purposes is a Goomba, is this line of questioning noteworthy? Or am I just pondering upon things that had been answered long ago?
Some of the concept art uses those weird non-badnik enemies, so I assume they were drawn before the TTS demo. I think the S1 protos having collision issues is just a matter of it not being easy to program a physics engine :P The TTS demo having such simple level design was probably because they wanted to focus on having something pretty to look at to build up publicity.
http://shmuplations.com/sonic/ https://www.famitsu.com/news/201606/24107383.html translation: https://pastebin.com/pQaK7w2d
