Infinite Money:
     While  playing  the  game,  hold ctrl+alt+shift+w. You will see a
white  _  on  the lower left of the screen when you did it right. Then
type  2061  and  press return. Then press a. Then hold shift+m and you
will  see your money rising. Hold shift+m until you have the amount of
money you want.

     To access all missions, edit the game.dat with notepad and change
the string:

Volume: -750, 0, -5?? 

to 

Volume: -750, 0, -580 

(The -750 can be various)