Mike Piazza's StrikeZone 

Bonus teams 
At the title screen, press C-Right, A, Down, Left.

Hidden message 
At the title screen, press C-Up, R, B(2).

View credits 
At the title screen, press R, A, Z, R, C-Right, A, B.

Cheat menu 
At the pre-game menu, press L, R, L, R.
Note: This code must be activated before the other pre-game menu cheats are enabled.

Devil's Thumb stadium 
At the pre-game menu, press Right, A, C-Up, L, A.

Always hit home runs 
At the pre-game menu, press L, A, Down, Right.

Super players 
At the pre-game menu, press B, A, R, B, A, L(2).

Better throws by fielders 
At the pre-game menu, press B, A, L, Down, Z.

Better plays by fielders 
At the pre-game menu, press B, A, R, Down, L, B.

Faster fielders 
At the pre-game menu, press R, A, Z, L, Down, A, Z, L.

Crazy ball 
At the pre-game menu, press C-Right, A, Z, B, A, L(2).

Better pitches 
At the pre-game menu, press B, L, A, B, R, Z.

Crazy pitches 
At the pre-game menu, press C-Right, A, Z, C-Up, R, B.

Faster pitches 
At the pre-game menu, press R, A, Z, L, Down.

Varied pitches 
At the pre-game menu, press C-Right, A, Z, C-Up, R, L.

Easy steals 
At the pre-game menu, press C-Left, A, Down, C-Up, Z.

Aluminum bats 
At the pre-game menu, press R, A, Z, B, A, L(2).

Red bats 
At the pre-game menu, press R, Down, B, A, Right.

Blue bats 
At the pre-game menu, press B, L, B, A, Right.

Psychedelic bats 
At the pre-game menu, press Z, B, R, A.

Low gravity 
At the pre-game menu, press Up, R, A, L.

Increased gravity 
At the pre-game menu, press Up, Down, L, Up, R.

Fast game 
At the pre-game menu, press L, A, Z, R, B, A, L(2).

Slow game 
At the pre-game menu, press Up, L(2), B, A, L(2).
Alternate sky 
At the pre-game menu, press C-Right, A, Z, C-Up, L, R, Z.