One of the fastest levels in Sonic history, Stardust Speedway is a highway adorned with musical instruments above an enormous city; like its namesake implies, the city glows with many lights. A statue of Dr. Robotnik can be seen undergoing construction in Zone 2, with girders and incomplete sections.
In the past, the background takes the form of a Roman/Greek-style city, complete with an acropolis and surrounding towns. The night sky is not as bright as it is in the Present due to the lack of technology, but some stars can still be seen. The zone is mainly entangled by vines as well. It also has a Gothic-styled building in the center of Zone 2.
In the Bad Future, Stardust Speedway has become a corrupted, polluted dystopian city underneath a large electrical storm with a completed statue of Dr. Robotnik in the center of Zone 2. The roads and instruments have become corroded and discolored, and no stars can be seen at all.
The Good Future looks like a giant futuristic amusement park, with bright pink and green colors dominating the landscape. It looks upon a vast bay with bright cities in the distance, and the Doctor Robotnik statue has been replaced by a beautiful cathedral in Zone 2.
Near the end of the level, Sonic is pitted against Metal Sonic in a complex race; should Sonic win, he will rescue the captive Amy Rose.
Stardust Speedway is the largest Zone in Sonic the Hedgehog CD. This is likely because such a speed-oriented Zone would be cleared too quickly if it was normally sized.
There are some paths in this stage which go up and down, much like Chemical Plant Zone. It is possible that this stage is influenced by Chemical Plant Zone.
The cathedral at the center of the good future timeline of Zone 2 appears to reuse the base of the Robotnik statue (seen being built in the present timeline of Zone 2)
In Sonic Generations, the unlockable remix of the North American/PC theme is listed as Stardust Speedway Zone.