The face of a hero, part 3

In mapping frames $80-$85, all three characters have a set of unique sprites that's only used while swinging across the monkey bars in Flying Battery Zone. Despite clearly sharing the same base as the standing rotation sprites however, at least Sonic's sprites appear to be noticeably less detailed, looking almost unfinished at times:

These sprites are included in standalone Sonic 3, which isn't too surprising when you consider how Flying Battery Zone was originally meant to appear earlier in the game. What's surprising is how they're identical to the sprites later found in Sonic & Knuckles. It seems like a rough version of the animation was first cobbled together, but then the stage itself got canned before the sprites were polished up, and eventually they just forgot about the whole thing.

Particularly interesting is the first frame, which doesn't share much of a likeness with the rest of the Sonic 3 sprites, but is more or less a perfect match for the standing sprite from Sonic 2.

This is probably holdover from the days where Sonic was still using adapted versions of his Sonic 2 sprites, suggesting that at one point they weren't just placeholders, but actually part of the game's design.