When playing Bal Bados against Tangram (the last boss), Bal Bados has a secret "Black Hole Bomb" that can be only performed on Tangram's stage. To use it, eject both of Bal Bados' arms (Left Turbo + Left Weapon attack, Left Turbo + Right Weapon attack), then press both Weapon attack buttons + Right Turbo. Bal Bados' arms will form a energy ball that does 25% damage against Tangram.