SOTA is a great demo that is rightly popular, but if you're going to pick a demo to marvel over the code, don't pick that one.
Theres nothing in SOTA that is very hard to do. The vectors for SOTA were hand traced, and that would have been laborious and annoying, but not difficult. Also, I have it on good authority (StingRay :-)), that the code itself is pretty awful (don't forget that the original SpaceBalls release had to be fixed by Skid Row for it to work on most Amigas; and that was even before AGA came out).
I'm guessing for 9-fingers they had automated the process of vectorising video frames.