Game Development:Sonic the Hedgehog 2 (8-bit)

From Sonic Retro

Sonic the Hedgehog 2 has gone through several changes over its development process. There are several rejected ideas, level designs, and other things that were left on the cutting room floor. The following details several of these things.

Early Game Design

These scans come from various magazines. They show Sonic 2 when it was in earlier stages of development.

Various

Title screen looks a bit different than final and lacks Tails.

Underground Zone

Here the roof is lower than in the final.

Wheels can be seen sparking.

Sky High Zone

Prototype screenshots show Sky High and Green Hills using some very basic checkered floors, similar to Sonic 1.	There's palette differences and more trees than the final game too.	This style is used in the opening cutscene, the ending and can be seen scrolling in the title card animations.	The handgliding section of act 2. The clouds seem to be different.
The lightning is also yellow rather than blue

Green Hills Zone

As Green Hills Zone shares many of the graphics from Sky High, it makes sense for it to have similar early checkered floors.	Again. It was likely this zone was due to appear first (instead of Underground Zone), but was altered last minute.	An early Map. The trees and flowers are different.	Again.
This battle takes place in Gimmick Mt. Zone in final. Rings can be seen.