God Mode:
     Note:  This  cheat  requires  a  basic  knowledge  of using a zip
program  and  a  text editor. Please back up any files before changing
them.

     Locate  the file game.pak in the installation folder. Rename this
file  game.zip and use your zip program (ie: Winzip) to open the file.
Now  extract  the  file\set\registry\lod.reg the the games folder with
the  full  path.  Now use a text editor (ie: Notepad) to edit the file
and change the easy setting to as follows:

{easy}
{enemy}
{health 0.0}
{accuracy 0.0}
{thickness 0.0}
{burst 0.0}
{firing_timeout 0.1}
{player}
{health_increase 99}
{burst 1.0}
{accuracy 99}
{thickness 99}
{health 99} 

     Now  you  can  save  the  file  and  add  it back to the game.zip
archive.  Save  the  game.zip  back to the original spot and rename it
game.pak.  Now  when  you start the game set it to easy and your units
will be Invulnerable.