Unlock Hidden Team
A hidden team, Tiburon, is included in Madden 64. To unlock the team go to Season mode and then to Front Office. Select Create Player and then go to name. Enter "Tiburon" into the field and then go down to continue. Save it and then go back to the main menu (using the B button). Now go into Exhibition mode and the team Tiburon will be selectable. They are giants.

Bonus Teams:
Enter one of the next names
code team
TIBURON ALL MADDEN
AT MADDEN ALL-STAR TEAM
SIXTIES 1960'S TEAM
SEVENTIES 1970'S TEAM
EIGHTIES 1980'S TEAM
HOWLIE 96-97 AFC PRO BOWL
LEI 96-97 NFC PRO BOWL
STATS MEN ALL TIME STATS LEADERS
ELEC ARTS EA SPORTS TEAM

Secret Stadiums
Go to create a player and enter the name as maitland click continue and save the player exit to exhibiion and under stadium select should be a new stadium. Do the same thing but type in San Mateo and there should be another new stadium.

Random Team Select
When you are selecting your team press C-up and C-right at the same time and the CPU will randomly select the teams.

Double Headed Coin
If you are calling the toss, you can make the coin have two sides. When the ref throws the coin in the air press down to tails then back up to heads about 2 seconds before the coin hits the ground. This will make the coin have two heads and you will win the toss.

Show End Sequence
At the EA logo when the game starts press L + R + Z

Touchdown Celebration
After going into the endzone press C-Left for a touchdown dance