Marble Garden Zone is the third zone in Sonic the Hedgehog 3. It is a ruin filled with plant life and an artistic look like you'd see in a painting. The player's character starts this zone once again by falling from the sky. By holding , one can obtain a Lightning Shield right at the start of the zone. Sonic and Tails fly into Carnival Night Zone, while Knuckles takes a tunnel from his boss area in Sonic 3 & Knuckles. Interestingly, if one uses Debug mode in Sonic 3 or Sonic 3 & Knuckles to take Sonic to Knuckles' version of the boss, Sonic will still enter the next stage by flying with Tails.
The first act contains the most Rings out of all the Acts in Sonic 3 with 636 in total, therefore, a Lightning Shield will prove useful if you want to get the most out of the rings in the level. Act 1 also has eight giant rings, the highest number in a single act of the entire game. This level reuses Oil Ocean Zone's "sinking pool" mechanic, only in a minor scale. There are also spinning antigravity tops which help to get around the vertically-orientated level.
||Use Sonic's Spin Dash Attack to crash through marble barriers and propel Sonic up steep hills as he explores this ancient city.
||Even though we used this pattern once before, we wanted to do another stage where the ground shakes ever since Sonic 1. In the first Zone, where Eggman is digging for jewels, we wanted that machine to appear and chase after Sonic from behind, something like that, but we didn't get to it this time.
— Yuji Naka
- Mantis — Green mantis with pointy (sharp) legs that jumps up at regular intervals.
- Spiker — A badnik with fake spikes that serve as a spring for Sonic.
- Bubbles — A blue, spike-wielding bubble.
- With Knuckles, you can get into Sonic's boss area in act 2. Use the blue spinning top to smash through the walls, then stand on the spikes, climb up the left wall and hit the Relief. Repeat this another two times and you're through. It's easier as Hyper Knuckles, as you can glide faster and can stand on spikes without losing rings, and even easier with debug mode.
- Alternatively, use the blue spinning top twice, interrupting the first time to clear out obstacles, and then go back for the re-spawned top; this way you don't have to lose rings.
- Sometimes, Tails will not appear for the act 2 boss, causing you to die.