In the main screen (the city map), type:

 ix1    All locations visible
 ix2    10 skill points for every marine
 ix3    500 equipment points for your squad
 ix4    Next mission

 YOUARESTUPID           Superlaser
 BUGGEROFF              Large Jump Pack
 GENEJONEGINGLELHON     A special soldier

 Collected with help from

 Martin Andersson, martin.hoganas@telia.com