There is a clear reason you can buy this game brand new for £10, and that reason is.... is terrible. The voice control seems like a nice touch, but you soon realise you are just talking out loud saying rubbish like 'Alpha one secure Yankee' . In the heat of battle you just keep yelling different commands at all your units and get frustrated.
The units are slow to react, and for a 2008 game they have no AI to speak of. Retreating away from a stronger opponent takes them ages and they usually get wiped out.
The 'rock, paper, scissors' style of battle is appauling, as is the range of units. Providing the unit you are attacking beats your unit in the 'combat chain' it doesn't matter is you outnumber them 6 to 1, they still wipe the floor with you.
Despite the fact there are many different maps, every game plays out the same way. All you have to do is find out what unit your enemy is using and then use the 'combat chain' to find out that units weakness.
This game could have been so much more and the fact it has Tom Clancys name is a joke. If you want to play this game, see if you can still download the demo, then play it over and over again, because thats pretty much what the whole game is like.