- Not to be confused with Carnival Night Zone.
Though it shares most of its aspects with carnival based levels in other Sonic games, Night Carnival is less modern and and more fancy, its buildings classical and defined, the level more akin to a long lived city made over for a night festival. It features lots of neon and bright lights and the player somehow is able to stand on lights.
Night Carnival has only two acts per story mode, and both story mode acts are identical. There are no differences between the levels, other than the music, which is the song "Ska Cha Cha", being different depending on the character the player has chosen.
A primary feature seen throughout the zone are switches that are required to be used to activate platforms and even Grind Rails in order to progress to progress throughout the stage. The zone also includes a unique spring that can be charged by holding Down on ; the longer it is charged, the further the player will be launched from the spring when releasing Down.
When playing as Sonic, Special Generators appear throughout this Zone which can warp the player to the fourth Special Stage for a chance to collect the green Chaos Emerald. As Blaze, the red Sol Emerald can be found after defeating the boss.
The boss is Egg Libra, which is fought in a circle on a high platform in the middle of the city in which Night Carnival takes place. One end has Dr. Eggman's/Eggman Nega's cockpit on it, and the other end has an electrified sphere. The boss will try to zap the player with electricity beams and also crush the player by slamming the sphere into the ground to make shock-waves. It even sends out little droids that come after the player. It can be defeated by hitting the sphere when it isn't electrified. This causes a seesaw effect; when the sphere is knocked up, the Eggmen's cockpit goes down, leaving it vulnerable to an attack. The boss can also be damaged by jumping on the little droids, which launch Sonic and Blaze up in the air so that they can hit the Eggmen without knocking them down.
- There's some chargeable springs in the zone that launch the player a great vertical distance when the player crouches on them (the longer you crouch, the higher you go). However, there's a particular spring that doesn't launch the player high enough to reach a platform; said platform can only be reached by using the Up+R Button moves (Hop Jump/Axel Tornado). Most players were unaware of this and got stuck there, and the spring became infamous just like the rotating cylinder in Sonic 3's Carnival Night Zone.
- Coincidentally, the two levels mentioned above, which are both infamous for their tricky gimmicks, are not only both carnival-based, but they are the fourth zone for Sonic and the reverse of each other's name; Night Carnival, Carnival Night.