Under the Surface of Classic Sonicさんのイラストまとめ

In between v0.02 and 510, before the background was changed to the final one, the palette was slightly altered to make the sky a little less saturated. This palette data can be found leftover in the final game.

(Left = v0.02, Right = Alteration before 510)

I haven't seen this documented anywhere, but there's a THIRD unused hanging sprite (on the very left). The unused hanging sprites are found in Tidal Tempest (which seems to be a hub for these unused sprites in the final, with leftover mappings as far back as v0.02).

There are some sprites that can be found in the 1996 PC version, but NOT the Sega CD version. These rolling sprites do exist in the v0.02 prototype, albeit unused. The shrinking sprites only exist via leftover mappings data in Tidal Tempest since 510; no tile data can be found.

22, goes with 21 above. Sonic is partially sunk in.

1F and 20, some kind of jumping animation?

Unused special stage animations for Sonic (thread)

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