Play all kinds of game to unlock hidden teams.

Team	How to unlock
Team "Africa Star"	At the title screen, press Up(twice), Down(twice), Left, Right, Left, Right, X, Circle, and Start.
Team "America Star"	At the title screen, press Up(twice), Down(twice), Left, Right, Left, Right, X, Circle, and Start.
Team "Asia Star"	At the title screen, press Up(twice), Down(twice), Left, Right, Left, Right, X, Circle, and Start.
Team "Euro Star"	At the title screen, press Up(twice), Down(twice), Left, Right, Left, Right, X, Circle, and Start.
Team "Legend '74"	Win seven times the International Cup on equal or higher level three.
Team "Legend '78"	Win six times the International Cup on equal or higher level three.
Team "Legend '82"	Win five times the International Cup on equal or higher level three.
Team "Legend '86"	Win four times the International Cup on equal or higher level three.
Team "Legend '90"	Win three times the International Cup on equal or higher level three.
Team "Legend '94"	Win twice the International Cup on equal or higher level three.
Team "Legend '98"	Win once the International Cup on equal or higher level three.
Team "World Legend"	Win the World League Mode Competition on equal or higher level three.
Team "World Masters"	Win the U-23 International Cup on equal or higher level three.
Team "World Star"	Win all ten scenarios on equal or higher level three.