Sonic Advance 3
Sonic is back, and this time he needs the help of all his friends to defeat the evil Dr. Eggman. In Sonic Advance 3, Sonic and Tails must once again team up with their friends Cream, Knuckles and Amy. Teaming up with any of the five characters gives you special attack moves: Sonic increases your speed, Tails increases your jumping power, Knuckles increases your attack power, Amy offers the hammer attack Piko Piko and Cream lets you perform a homing attack. With a Game Boy Advance link, you and three of your friends can compete in multiplayer mode.
Story
Before the events of the game, Dr. Eggman builds a robotic assistant called Gemerl that uses parts of the robot Emerl that was destroyed in Sonic Battle. Eggman tries an experiment with the Chaos Emeralds to perform the Chaos Control technique, but it goes wrong and tears the world apart. This action separates Sonic and Tails from Amy, Knuckles and Cream, all of whom Eggman finds and captures to build a segment of his upcoming empire on each part of the planet. Sonic and Tails travel through the game's seven levels to recapture their friends and get back the emeralds. The final boss battle takes place in the Altar Emerald Temple. If the player defeats Eggman there without having all seven Chaos Emeralds, Eggman and Gemerl escape and fall off the edge of the temple. Peace is restored to the world and Omochao snaps a photo of the five heroes. However, the game tells the player that the emeralds still need to be collected for the true ending. When the player defeats Eggman in the temple with all the Chaos Emeralds, Gemerl stops escaping with Eggman and attacks Sonic, scattering the Emeralds. Gemerl uses them to take on a giant spherical shape, but Sonic also uses their power to gain his Super Sonic form. With Eggman's help, Super Sonic destroys Gemerl. Tails later finds Gemerl's broken body on a beach, repairs it and reprograms it. The game ends when Cream plays with the now non-aggressive Gemerl at her mother's Vanilla house.