Desert Dazzle was a newly designed Round that Christian "The Taxman" Whitehead planned to add to his officially licensed 2011 remake of Sonic CD but ended up cancelling.
Desert Dazzle was inspired by the scrapped Sonic the Hedgehog 2 level Dust Hill Zone, with The Taxman getting as far as finishing artwork and level layout for the Present, before cancelling it and removing it from the final game. A test map for the Round exists within the game's files.
A mock-up image of Desert Dazzle can be found by entering a special code on the music player/sound test screen: Simply enter PCM:32 and DA:8. This code will also send the player the Stage Select menu with Tails as their chosen character.
The level was an original creation based on the creator's own idea. The Taxman had created an early demo track for the level, but multiple regional soundtracks hadn't been taken into account yet. The demo track ignored the multiple regional soundtracks, so new music would have to have been created for each region.
In Sonic Mania, a new Zone called Mirage Saloon Zone takes inspiration from Desert Dazzle and re-uses some of its graphics.