Concept Art

Concept art for Cream the Rabbit. From the 25th Anniversary Party.
Zero concept art from the Sonic Advance 2 Prima Guide.

Early Versions

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

As seen in a trailer video from Sonic Mega Collection, originally Sonic Advance 2 had a simpler title screen. Here the checkered background always scrolls downwards.
An early character selection screen still using Sonic Advance images and lacking diagonal "SA2" text in the background.
An early level select. In the final, the Music Plant area appears larger and there's a chaos emerald count.
When Cream was first shown Sonic Team made the mistake of keeping Amy's life icon complete with broken palette. There is also no sign of Cheese, and the only time four characters would appear on screen is through multiplayer mode.
Gd-sadv2-5.jpg

In an earlier version of the final battle, Super Sonic's sprites were re-used from Sonic Advance 1, rather than being re-drawn.