No bodies:
Press Start to pause game play, then press R1, R2, R1, R2, Up, Down, Left, Right. 

Big ball:
Press Start to pause game play, then press L2(2), R1, Left(2), Right, R1, R2. 

Big bat:
Press Start to pause game play, then press Right, R1, Left, L1, R2(2), Left, Right. 

Small heads:
Press Start to pause game play, then press Up, Down, Up, Down, R1(2), L1(2).

Big heads:
Press Start to pause game play, then press Left(2), Right(2), L1, L2, R2, R1.

Big feet:
Press Start to pause game play, then press Right, Left, Right, Left, L2, R1, L1, R2. 

Fast players:
Press Start to pause game play, then press Left, Right(2), Left, L1, R1(2), L1.

Slow players:
Press Start to pause game play, then press Left(2), Right(2), R2(2), L2(2).

Programmer names:
Press Start to pause game play, then press R1, R2, Right(2), Left(2), L2, L1.

Super player:
Enter one of the following case-sensitive player names at the player creation screen. Trade him to your team from the free agent screen. He can hit 606 ft. homeruns. 

SCOTT MURRAY 
JOE MURRAY 
VIVIAN MURRAY 
CHRIS MURRAY 
BRIAN MURRAY 
MR BASEBALL 
LEAD PROGRAMMER 
HEAVY LUMBER 
SLUGGER _ (Note: Enter a space as the last name)