Revision .00 was the first release of Sonic 2, and had been difficult to find on cartridges. It is assumed that this was only used on a few runs of the cart before rev.01.

It has been knowingly avaliable in ROM form since rika_chou released it on the 29th of July, 2005.

Revision .00 had quite a few minor errors, which were later fixed in Revision .01. Here are a few which can be shown:

The end of level sign post from Casino Night Zone act 1 was originally placed a little too far down, you can see the bottom of the post poking below the floor.

Submitted by: BMF54123

A spelling error in the credits screen was in rev.00. Instead of "THOMAS", it would show "TOHMAS".

Submitted by: Rattleman

In rev.00, an error would occur if you had 999 rings, and opened up a Super Ring Box. Instead of not registering [as it would cause overflow], the counter basically corrupts.

There were many other very minor alterations, mostly minor bugs or simply cleanup code. These alterations are documented over at Hacking-Cult by drx.

The largest misconception with Revision 00 was that it held over Picky the Pig from Sonic 1, and placed him in Casino Night Zone. This, for a long time, was used in order to help find Revision 00. Many claimed to have a cart with a pig-infested Casino, but it was never dumped. In the end, once the 00 release was dumped, we finally found that there were NEVER pigs in Casino Night Zone, and that it had all been a case of mistaken identity.

Both the pig and bear look similar, especially on a Television screen. This is why it had taken so long to discover revision 00!