Sonic Advance Game Boy Advance

Gameplay

The game follows Sonic and his friends as they travel through various zones in order to stop Dr. Eggman from taking over South Island. The game features four playable characters; Sonic, Tails, Knuckles and Amy. Each character has the same moveset as they did in Sonic the Hedgehog 3 and Sonic & Knuckles, with the addition of a melee attack. Each character has a special ability, such as Sonic's splice shield, Tails' flight and Knuckles' gliding and climbing abilities. In her playable 2D debut, Amy cannot perform the Spin Dash or get into ball form when jumping like the others, and must rely on her Piko Piko Hammer to defend herself, making her unique amongst the characters. Grind rails first introduced in Sonic Adventure 2 also make their first 2D appearance. Sonic and Tails can also be used at the same time during the story by inputting a cheat code at the character selection screen. When playing as both characters, the gameplay is similar to that of Sonic the Hedgehog 2: The player can only control Sonic and a CPU-controlled Tails follows him.

Special Springs can be found near the top of certain acts. Each normal zone contains one Special Spring, except for Ice Mountain Zone which contains two: one in each act. By jumping onto these springs, the player can reach a Special Stage—each spring goes to a certain special stage every time it is jumped on. The stages see players fall down a tube on snowboards while trying to earn enough rings to complete the target amount. By winning the stage, the player receives a Chaos Emerald, although there is only one emerald per stage, so the same stage cannot be repeated for multiple emeralds. Unlike most other classic 2D Sonic games, the Emeralds are "shared" between all the characters. Once the player has collected all the Emeralds and completed the X-Zone with all four characters, they can access the Moon Zone by completing the X-Zone again with Sonic.

Tiny Chao Garden

Sonic Advance, like Sonic Advance 2 and Sonic Pinball Party, features an extra game called the Tiny Chao Garden, in which players can raise Chao. Players can transfer their Chao between the Tiny Chao Garden and the Chao Garden from the GameCube versions of Sonic Adventure and Sonic Adventure 2. Tiny Chao Garden is more limited than the Chao Garden: Chao don't age, can only interact with fruit and three toys (which must be bought in the Tiny Chao Garden itself), and only one Chao can be in it at once. An egg can be stored in the garden too, and hatches as soon as there is no Chao in it. Chao can only leave the garden by being transferred to the Chao Garden or by running away when players don't take care of them. Fruit, toys and eggs must be bought with the rings collected in the normal game or two minigames. Rings, fruit and eggs can be transferred to the Chao Garden, but not from it.

Source: Wikipedia