Get 1996 Packers for 1 player mode:
In training camp finish the Passsing Drills
Get 1964 Cleveland Browns for 1 player mode:
In training camp finish the Kicking Drills
Get 1983 Raiders for 1 player mode:
In training camp finish the Tackling Drills
Get 1977 Cowboys for 1 player mode:
In training camp finish the Running Drills
More Classic Teams:
Use classic challenge mode to defeat teams to unlock them
Unlock Stadiums:
Finish the following number of seasons in Dynasty mode to get the stadium indicated
5 – Pyramid Stadium
10 – Samurai Stadium
15 – Tumbleweed Stadium
Stadium Unlock:
Put in the following names for your user name to unlock the stadium
Flowery – Pansies Stadium
Barracks – Commandos