Gem X

Here are the level codes.
They have to be typed on the main menu.
Level B : EARTHIAN   Level C : KENICHI   Level D : INOKUMA
Level E : BURAI     Level F : BADMAN   Level G : NETWORK
Level H : YOKOHAMA   Level I : EXACT     Level J : X68000
Level K : TURRICAN   Level L : REDMOON   Level M : CAMPAIGN
Level N : MEGAMAN   Level O : SYVALION   Level P : FMTOWNS
Level Q : CHIERIE   Level R : GAMERION   Level S : ZAWAS
Level T : ROBOTECH   Level U : POPULOUS