Soniclash! is a mini-game featured in Sonic Battle, exclusively for the game's multiplayer function. It is unlocked from the beginning of the game. Here, anyone from two to four players, each with their own Game Boy Advance system, can play together. Howeever, only one Sonic Battle Game Pak is needed to serve as the host.
Soniclash! is centered around a pinball-type gameplay. When starting the game, the host player must decide how long the match is going to last, which can be either 60, 120, or 180 seconds. Once the choice has been made, the playable characters are dropped onto an octogon-shaped area with no railing and which hovers over what appears to be the sea. The playable characters themselves will be rolling around on the field in a Spin Attack stance. From there, the player's objective is to knock their opponents off the field. However, the playable characters will return to field after a few seconds should they fall off it. To aid the players, their character can perform a Spin Dash-like dash, although it makes the playable character harder to control. Each time a player manages to knock an opponent off the field, they earn one point. However, each time a player rolls themselves off the field, they will lose one point. It should be noted that a player's point tally can decease into negative integers. The match ends when the timer hits zero; the winner of the match will be the player with the highest point score.
To move around on the field, the player must use and to dash, they must press .
List of playable characters
When beginning Soniclash!, the players are given one out of four playable characters, with the character assigned being based on the player's number. The different characters given to the players are as follows: