Sonic Advance was released on December 20, 2001 in Japan and on February 4, 2002 in the U.S. This was the first game on the Gameboy Advance system with Knuckles as a playable character. This game is very similar to the 2D games from the Genesis/Megadrive.

KNUCKLES' GAME

Knuckles is just one of the group attempting to stop Dr. Eggman from creating the "Eggman Empire." As far as abilities go, Knuckles still has his ability to swim from Sonic Adventure 2 within this game, which is something that can come in handy in Ice Mountain.

KNUCKLES' ZONES

Each zone has two acts except for Egg Rocket, Cosmic Angel, and X. Egg Rocket and Cosmic Angel are considered acts 1 and 2, respectively, for the sixth zone of the game. X is the final zone and contains three different bosses.
Neo Green Hill
Secret Base
Casino Paradise
Ice Mountain
Angel Island
Egg Rocket
Cosmic Angel
X

POWER-UPS

1-Up: Gives an extra life
5 Ring: Worth 5 rings
10 Ring: Worth 10 rings
? Ring: Worth a random amount of rings
Electric Shield: Attracts rings and prevents Knuckles, Sonic, Tails, or Amy from losing their rings for one time when either hit by an enemy or falling into a trap
Green Shield: Prevents Knuckles, Sonic, Tails, or Amy from losing their rings for one time when either hit by an enemy or falling into a trap
Invincibility: For a short time, nothing can hurt Knuckles, Sonic, Tails, or Amy
Sneakers: Increase Knuckles, Sonic, Tails, or Amy's speed for a short time

SPECIAL STAGES

This is where you obtain chaos emeralds. You need to find the Special Spring within each zone to access these stages. You have to collect the required number of rings within each stage to get the chaos emerald.