The seven Chaos Emeralds are the most important collectibles in Sonic Advance. Collecting all of them is essential to unlock the true final boss and achieve the good ending. Each Emerald is obtained by successfully completing a Special Stage. To access a Special Stage, you must find a large, glowing Special Stage Ring hidden within each of the first six zones (Neo Green Hill, Secret Base, Casino Paradise, Ice Mountain, Angel Island, Egg Rocket). There is one Special Stage Ring per zone, and each ring leads to a unique Special Stage. Once you enter a Special Stage, you'll be on a half-pipe track, similar to Sonic 2. The goal is to collect a specific number of rings before time runs out, while avoiding bombs. The required ring count increases with each subsequent Special Stage. Mastering the controls within the half-pipe, especially knowing when to jump and when to stay on the ground to collect rings, is crucial. If you hit a bomb, you lose a significant number of rings. If you fail to collect enough rings, you'll be ejected from the Special Stage without the Emerald, and you'll need to find the ring again in a different playthrough or retry the stage. Tails' flight can make finding the Special Stage Rings much easier in the main acts.
