Agent Hugo Operation Lemoon Twist

Open Game.ini file with a texteditor (for example: notepad), search for
these two line QuickBoot=0 and ShowVersion=0. Change the 0 to 1 to activate the following cheat effects:

QuickBoot=1
Will give you access to a build in level selector

ShowVersion=1
Will give you access to a build in debug menu, with the following cheat options:
Collect All Lemons
Soak test
Unlock all levels
Jump to End of Level
Invulnerability

Also make sure EnableDebugMenu=1 is there (the game should generate it
by itselves, but check to be sure).