Sonic Advance 1: Part 6: Egg Rocket Zone (Sonic)
This level has a unique theme to it that also ever so feels like turning the Sonic 3 & Knuckles' transition between Sky Sanctuary to Death Egg to a full Zone.
First, you start in a canyon, but then quickly reach inside a rocket. Take note of how the time changed once you get in.
This Zone has you try to climb higher and higher through different layers of the Egg Rocket on a countdown. If time runs out, you'll die and will have to retry a layer. These count as you Star Posts.
You keep doing this until the game tells you that you cleared the Zone. However, the game also tries Egg Rocket as Act 1 of 2 Zones.
The next Zone, Cosmic Angel is the Act 2 of this pairing. There are no Special Springs in Egg Rocket, but the final one is in Cosmic Angel.