I just found a free game called
enemy nations.
You can download a free copy here (I think it may also be hosted on filefront):
(306 MB) download.
The support forum is:
support forum.
A description of the game (excerpt from
hotu which also links to a download pdf manual):
Enemy Nations is one of the best and most sophisticated real-time strategy games ever made. It's also a game you've probably never played, because its slated publisher went out of business shortly after the game's release, forcing developer Windward Studios to sell the game exclusively from its website. If you ever hoped you could have more resources and do research in Red Alert, or that you could control your soldiers more directly and have a simpler economy in Settlers, then Enemy Nations, as a game sitting squarely between the two, fits the bill. It's neither a simple action strategy game, nor is it a straightforward god game with token battle elements. Rather, it's an isometric strategy game which takes influences from half a dozen existing games and tries to blend them into something new, and in most aspects, succeeds admirably.
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My $0.02: Apparently, there are many other games of this genre like Supreme Commander, but I've never played them. This is a good free introduction to this rts strategy genre that runs nicely on today's PCs.