I dont know if this has been said or not, but a new game got me thinking. What if the last secret isnt unlockable without a certain Midway game save on your memory card? Since you can play as Sub-Zero in MLB Slugfest 20-04, why not have a game saved from a earlier Midway game be the key to unlocking the possible last secret? I went to Midway to find a list of the games for the PS2, GameCube and XBOX and came up with this list.
Defender, Dr, Muto, ESPionage, Fireblade, Freaky Flyers, Freestyle Metal X, Gauntlet Dark Legacy, MLB Slugfest 20-03 and 20-04, NBA Ballers, NFL Blitz 20-02-03, NHL Hitz 20-02-03, Red Card 20-03, and Spyhunter. MAYBE it is in one of the previous games from Midway? What do you all think?