An interesting concept with disappointingly sloppy execution.
Well, that's not how the original CDS is. While the premise is interesting enough, and the actual scope of the game is impressive, the graphics, while not a complete eyesore, are quite bland and sometimes plain ugly. The controls are decent enough, though they can be poor during driving segments. The sound is not so good, with weak gun sounds, strange and badly synced reloading sounds, annoying voice work at times, and simplistic music clips. Gameplay is usually laughably easy, and sometimes clunky feeling, with enemies at times feeling sprinkled throughout the huge desert terrain that you traverse in the game.
While CDS is unimpressive technically, and somewhat bland from a gameplay perspective, the game is salvaged from incineration in game hell by its wonderful cooperative options. The game can be played alone, but it's recommended that you play with 1 other person, though the game can accommodate for up to 4 (in-game you control 4 different soldiers, so for co-op, the team is simply split to accommodate more players). The game has a heavy emphasis on teamwork, so it's only natural that it would be more fun with you and a buddy working together.
When the day comes to an end, CDS is a middling game, salvaged from complete disaster by it's excellent coop mode - its one redeeming quality. In the end, I can't recommend the game for a price over maybe 5 or so dollars. It simply isn't worth any decent sum of money, with other much better titles out there to choose from, not to mention it's sequel, CDSII, a much improved version of this rather drab game. In the end, you can't punish the game too much for existing, as it's important as a stepping stone and learning block for its sequel. It's probably not worth your time, but it is worth your appreciation.