Here is a code for the mystery stadium:
Go to the Select Stadium screen and enter:
L1, R1, L1, R1, Start.
For Monster Homeruns enter as the pitcher begins his windup:
Up, Up, Triangle, Triangle, Up, Up, X, X.
A chime will sound when the cheat is engaged.
Entering the names of selected programmers (found in the credits at end of manual) will give you some cool players in Custom Player mode. Try 'Erik Kiss'...Super Center Fielder:
Create a new player named "Dennis Hirsch" and put him at center feild. He runs 4 times faster than a regular player!
For a super pitcher, create a custom player named "Jon Spencer". Trade him from the free agents to any team you want. Jon can throw up to 159 mph pitches!
Create a custom player named "Mike Swanson" and trade him into any team. Whenever he bats, he hits the ball straight towards the pitcher! Some times he hits it so hard the pitcher gets injured!
Thanks to Revolution readers Brett Vogel, Jason Sommerfeld and BCasper!