Jikkyou Powerful Pro Baseball 6 

Bonus stadiums 
At the stadium selection screen, press C-Up, C-Left, C-Right, C-Up, C-Right(2), Z, C-Left, C-Right, C-Left, C-Right, Start.

View all player statistics 
At the status screen, press C-Up(2), C-Down(2), C-Left, C-Right, C-Left, C-Right, Start.