Run summary

Sonic Chaos in 14:28.55 with all emeralds. I felt that collecting the emeralds would be the only way of making this movie remotely entertaining, as many of the strategies used are, while more optimised in this run, very possible in real time.

Emulator information

Dega v1.16, MAME core. I haven't touched any of the settings, so the defaults should work fine.

Timing notes

THIS IS VERY IMPORTANT, MAKE SURE YOU READ IT BEFORE ANYTHING ELSE.
This run appears not to beat existing unassisted records at The Sonic Center. However, the reason for this is that the PAL version of this game butchers the timer such that for the same input it only takes 5/6th the time. I elected to use the NTSC version, which provides a faster and (hopefully) more entertaining movie.
Additionally, the timer in this game acts similarly to the one in Sonic 2 (carries over subseconds from previous levels) so that can add on up to an additional second.

General notes

This game moves a bit faster than Sonic 1 and 2 for the SMS/GG, as Sonic gains two new moves: the spindash (down+1) and the peelout (up+1). The peelout is faster, but has its disadvantages, namely, you cannot roll once you start a peelout until you either jump or brake (or get hit, I suppose, but that's just a more extreme form of braking :P).
Collecting five Chaos Emeralds will trigger the best ending, after Robotnik drops the 6th after Electric Egg 3.
Oh, and as with many Sonic runs on this site, bonus screens take up way too much time. It's not as bad as either of the first two games though.

Level notes

Turquoise Hill 3: This glitch was discovered by Sonikkustar, and it enables you to ignore the running off the screen at the end of each act 3. It doesn't work, however, in Mecha Green Hill 3, due to the way the boss area is laid out.
Gigalopolis 2: When planning my special stage route, there were three certainties: Sleeping Egg 2, Aqua Planet 1 and Aqua Planet 2. All three had 100 rings practically on the TA path, which made planning very easy. The next two were trickier; I opted for Electric Egg 1 which has a row of six ring boxes, even though collecting them is rather slow, and this. This level required a very specific route to get the 30 loose rings in addition to the easy seven ring boxes.
Mecha Green Hill 2: I tried everything I could think of but you just can't get enough height off the spring to land straight on the platform above :(
Electric Egg 1: You can't stand on the pipe, that's why I have to spend so long collecting the six boxes.
Electric Egg 3: I'll leave you to watch this one :)
Thanks go out to Sonikkustar - made a number of attempts at TASing this game, most of which had at least something I could take out of them, and DarkspinesSonic, holder of all the unassisted level records at TSC.
Enjoy the run!

adelikat: Replaced the submission file on author's request that fixes a mistake on the last boss. TODO: author mentions how much of an improvement it is.
mmbossman: After some clarification that my copy of this game is really a (EU) version as opposed to (E), I can't find any reason not to give this the green light. I hope a future version might find some techniques to decrease lag, however. Accepting...