- Not to be confused with the Night Carnival Zone of Sonic Rush.
Carnival Night Zone lives up to its name — it's a theme park! In the fourth zone in Sonic the Hedgehog 3, everything's pretty much the same, except that there are many more hidden areas than in other zones and a few more toys. There's the cannon, which will launch you in the direction of your choice. Of course, don't forget the anti-gravity pads and balloons to bounce off. There are large, black wheels to get dizzy on, and the unforgettable rotating barrels; note that not all barrels move very far. Sonic and Tails enter the zone by flying from Marble Garden, while Knuckles comes in through a tunnel in S3K. At the end of the Zone, Sonic and Tails are launched out of a cannon to IceCap, whereas Knuckles will use a teleporter to change zones.
It is interesting to note that Act 2 is one of the only three levels where Knuckles does not fight a boss to advance to the next zone (the other two being Lava Reef Zone and Hidden Palace Zone).
Barrel of Doom
Near the end of Act 2, just after the player has turned the power back on to the zone, Sonic will run into a small area with a barrel that gates the way forward below it. There are many barrels in this zone, but this is the only "required" one. Because of that, many players of Sonic 3's contemporary release had no idea how to use the barrel and progress, and the barrel became dubbed the infamous "Barrel of Doom".
To actually use a barrel, you press and on the D-pad as you move up and down on the barrel to shift its weight; you can use this momentum for either high jumps or getting through gaps, such as the one here. Jumping will help a little for the high jumps, but it's not enough to get through the gaps.
When playing Sonic 3 & Knuckles, Knuckles takes a different path through Act 2 and doesn't have to worry about any of this.
||Night life on the Floating Island is exciting. Bounce and flip your way across this colorful Zone which is filled with anti-gravity platforms. However, beware of many traps that are set along the path.
||While developing in America, we would see these portable carnival rides come in around shopping centers, and that was the idea we went with for this stage. When you think of carnivals of course there are Ferris wheels and teacup rides, but it seems like generally there were a lot of things that just pushed and spun you around really fast (laugh), my main memory was that they were unusually scary!
— Yuji Naka
- Batbot — Bat with a lightbulb for a behind.
- Clamer — A blue clam that can serve as a spring, much like the Spiker.
- Sparkle — An electric "grenade" that usually comes at you in pairs.
- Not really a glitch, more a level design oversight: with Knuckles, it is possible to get to Sonic's version of the second act even without using debug mode or exploiting a glitch. At the very beginning of the act, instead of running down the very first red and white spinning bar, jump and glide repeatedly to the left until you reach its top, then glide to the right. You will find yourself in an upper route, and later in Sonic's main route. In the area preceding the boss battle, the two shafts which would normally propel the character upwards don't work, so Knuckles has to climb inside the upper shaft to get to the boss (which he gets to fight, appearing correctly as Eggrobo). Falling down the lower shaft and going past where Knuckles is standing during Sonic's playthrough reveals a non-functional teleporter. After the boss battle, Knuckles has to use the cannon to get to the next level, but will still be seen teleporting in at the beginning of IceCap Zone.