X = first icon, Y - second, and B = third. A code such as 2-4-2 Up requires you to press X twice, Y four times, B twice and then Up on the D-pad.

Effect Code
16-inch softball mode 2-4-2 Down
Alien team 2-3-1 Down
Atlantis stadium 3-2-1 Left
Big head mode 2-0-0 Right
Blade bat 0-0-2 Up
Bobblehead team 1-3-3 Down
Bone bat 0-0-1 Up
Casey team 2-3-3 Down
Coliseum stadium 3-3-3 Up
Dolphin team 1-0-2 Down
Dwarf team 1-0-3 Down
Eagle team 2-1-2 Right
Empire Park stadium 3-2-1 Right
Evil Clown team 2-1-1 Down
Extra time after plays 1-2-3 Left
Forbidden City stadium 3-3-3 Left
Gladiator team 1-1-3 Down
Horse team 2-1-1 Right
Ice bat 0-0-3 Up
Lion team 2-2-0 Right
Little League mode 1-0-1 Down
Log bat 0-0-4 Up
Max batting 3-0-0 Left
Max power 0-3-0 Left
Max speed 0-0-3 Left
Midway Park stadium 3-2-1 Down
Minotaur team 1-1-0 Down
Monument stadium 3-3-3 Down
Napalitano team 2-3-2 Down
Olshan team 2-2-2 Down
Pinto team 2-1-0 Right
Rivera team 2-2-2 Up
Rocket Park stadium 3-2-1 Up
Rodeo Clown team 1-3-2 Down
Rubber ball mode 2-4-2 Up
Scorpion team 1-1-2 Down
Spike bat 0-0-5 Up
Terry Fitzgerald team 3-3-3 Right
Tiny head mode 2-0-0 Left
Todd McFarlane team 2-2-2 Right
Unlimited turbo 4-4-4 Down
Whiffle bat 0-0-4 Right