I missed this one yesterday, naughty me, Stormregion have released their 2001 cartoon action/trategy title S.W.I.N.E. for free as a Christmas present. I remember playing this one quite well and it was fun as well as funny, reminded me of Cannon Fodder a lot.

Either way, for the price of a 716mb download, you have pretty good game to play without spending a penny. You can grab it at 3dGamers