Hidden Stadiums:

To unlock these stadiums, enter the desired code in
the Secret Code screen. 

      Alpha Blitz -- PANCAKES 
      Antarctica -- XMASGIFT 
      Circus -- 3RING 
      Cosmodome -- SPACEBALL 
      Dodge City -- WILDWEST 
      EA Sports -- ITSINTHEGAME 
      Gridiron -- KLAATU 
      Maddenstein -- COUNTMADDEN 
      NILE Hi -- DENILE 
      North Pole -- XMASGIFT 
      Salvage Field -- TENANU 
      Tiberium -- FEEDTHELIONS 
      Tiburon -- WEPUTITHERE 
      Tiburon Bros. -- COTTONCANDY