In a two-player game, pause the game when you're at bat and press B, Y, B, Y, and Select.
If you hit a fair ball doing this at bat, it will count as a homer.
In an outdoor stadium, pause the game and press Select, Down, A, Y. Once the game view changes, day will turn into night or night into day.
At the Title screen, press A, B, X, Y, Up, Down, and Select. The longer the season
completed, the more teams you'll have to choose from.
Pause the game, press A, Right, Down, Left, A, Down, and Select.
Press Left, A, Right, Down, Y, and Select to slow the game down.
Press Left, Y, A, Right, and Select to randomize the opposing pitcher's throws.
Press B, A, Down, B, A, Left, and Select to get super fast pithes!
Press B, Y, B, Y, and Select. If you get hit and the ball is fair, you get a home run!