Choose "Random Map" mode and enable the "Cheat Codes" option at the setup screen. Press Enter during play, type one of the following codes, then press Enter again.

Code                           Result
my name is methos              All Resources
all your base are belong to us 100,000 of each resource 
atm                            1000 Gold
you said wood                  1000 Wood
rock&roll                      1000 Rock
creatine                       1000 Iron
boston food sucks              1000 Food     
asus drivers                   Reveals Map
somebody set up us the bomb    Wins Game
ahhhcool                       Lose Game
headshot                       Remove Objects From Map
brainstorm                     Instant building and train/create
i have the power               Restore energy to mechs/robots
friendly skies                 Planes refuel in the air
bam                            Show entire map and remove FOW
the big dig                    No resources
columbus                       See fish and animals
the quotable patella           Level 10 upgrade for all units
boston rent                    Lose all Gold
uh, smoke?                     Lose all Wood
slimfast                       Lose all Food
girlyman                       Lose all Iron
mine your own business         Lose all Rock
coffee train                   Buildings completed

Thanks to Revolution readers Onizuka and Tom Craster!