The Simon Wai prototype of Sonic the Hedgehog 2 was built in early August 1992. The prototype is named after Simon Wai, who found it on a Chinese GeoCities page in 1998. However, it is believed to have first been leaked in September 1992 and distributed through BBS (bulletin board system) numbers. The origin of the actual ROM image is unknown. Magazines from the time attributed the leak to a specific magazine, while Yuji Naka stated in 2005 that it came from a demonstration cart that was stolen from a New York toy fair in 1992.
In any case, this build was one of the first video game prototypes to be dissected in detail. It kickstarted interest in prototypes for not only the Sonic fanbase, but the gaming community at large.
Wood Zone is a scrapped Zone found in the prototype. It seems that only a small portion was ever implemented and did not get too far. What exists of the level quickly ends because of a ramp that has a solid platform blocking the top of it, which is impossible to get past without Debug Mode. Even then, the rest of the level is incomplete, with a nonfunctional conveyor belt near the top. Act 2 is empty, containing nothing but Sonic and Tails falling to their deaths.