Emergency Mayhem was first announced for the PlayStation 2 and Xbox at the 2004 Electronic Entertainment Expo, published and developed by Acclaim. However, the game was canceled when Acclaim filed for bankruptcy in September 2006. In May 2007, Warner Bros. purchased the rights to the game. Warner Bros. announced the game would be released for the Wii and they would publish the game, while Codemasters would develop the game. Then, in December of the same year, Codemasters announced they had taken over the publishing rights, and Supersonic Software Ltd took on developing the game. In the end the game was released for the Wii in 2008, even if there are probably some differences from the original XBOX and PS2 versions. [Info from Wikipedia]
A playable prototype of the Xbox version was leaked and it’s currently in the hands of some collectors. Stone from the Assembler Forum has one of these protos and he shared some screens and videos from his build!