So far, there are no cheat codes, but there are some command-line
switches.
These are all the possible switches:
/SKIP simply puts you right into a level with going thru any other
screens.
/LEV is the switch that goes to any level (but with the default
weapon and health as if starting a new game in level 1).
The syntax is: LR /LEV LEVELS\MISSxx
where xx is the level number.
Apparently what this does is replace level 1 with the given level.
This means that starting a new game will give the mission briefing
for level 1 and show the "Loading Level 1" screen. Saving
and loading saved games works just fine, but if the game is exited
and restarted, the same command line must be used to restore a saved
game.
The level numbers and the MISSxx files don't exactly match up.
Here's the table:
Level 1 = levels\miss01
Level 2 = levels\miss07
Level 3 = levels\miss04
Level 4 = levels\miss05
Level 5 = levels\miss06
Level 6 = levels\miss08
Level 7 = levels\miss09
Level 8 = levels\miss10
Level 9 = levels\miss11
Level 10 = levels\miss12
Level 11 = levels\miss13