Type in POOSLICE as your name to enable the cheats.  When your done
typing it in a weird sound will start playing.  That's telling you
that the cheats are on. Then you can delete the name and type in whatever
you want.

At the research screen:
0   Add more options to research menu
U   Finish a days worth of research

During the game:
ALT-C     Complete the level
ALT-T     Teleport active agent to cursor location
SHIFT-Q   Full weapons and health

Command line parameters:
/m  Allows you to hit the . key at the menus to get 10,000 credits
/mx Skip to that mission (where x is a number between 1 and 108)

To use the command line parameters, start the game with main /w /g and add 
them to the end of the line or add them on that line in the PLAY.BAT file.