Cheat: Legends
Enter LEGENDS as the coach’s name to unlock Babe Ruth, Mickey Mantle, Roberto Clemente, and Marc McGwire.
Unlockable: Mr. Clanky
The way to get Mr. Clanky is to beat the game and go to the main screen. Then, look at the batting practice mode and you will see a tiny Mr. Clanky. Click on him and it will make a squishy noise and then you will be able to have Mr. Clanky. (Only works on single player mode.)