Carmageddon   

 Type these in during gameplay:

            GOOGLEPLEX - Under Water Ability
            GIVEMELARD - Mega Bonus (loadsa Money)
            SPAMSPAMSPAMSPAM - Pedestrians Glued to Ground
            SMALLUDDERS - Giant pedestrians
            SUPERHOOPS - Explosive pedestrians
            IGLOOFUN- -Hot rod (Huge Speed Increase)
            FUNNYJAM - Turbo Pedestrians
            IHAVESOMESPAM - Gravity has Gone Strange
            MOOSEONTHELOOSE- - Pinball Mode
            CHICKENFODDER - Bouncy Bouncy
            BUYOURNEXTGAME - Jelly Suspension
            ILOVENOBBY - Pedestrians Shown on Map
            RUSSFORMARIO - Electro-Bastard Ray
            HAMSTERSEX - Blind Pedestrians
            NAUGHTYTORTY - Pedestrian Respawn
            INTHELOFT - Drugs
            BOYSFROMTHEBUSH - Grip-o-matic Tires
            TRAMSARESUPER - Pedestrian Harvest
            ISLANDRULES - Vesuvian Corpses
            RABBITDREAMER - Gravity from Jupiter
            BIGBOTTOM - Bodywork Trashed
            SPAMFORREST - Instant Handbrake
            SPAMFRITTERS - Free Repairs

            In the main selection screen where it says start race, type 
            kevwozear, and it gives you every car in the whole game and all the 
            armor and so on. Also, in dos you can go to the carmageddon 
            directory, and type carma.exe -german and it has robots instead of 
            pedestrians.