DEFCON is perhaps the only game which allows you to commit a global-scale nuclear genocide...and award you for it.
Although simple in design, it is probably one of those rare games which have an "timeless" stamp on them. The slick, elegant graphics that pay homage, or rather, "totally worship" classic films such as Dr. Strangelove and WarGames, serve their purpose in a most appealing way. You may only see one screen in the vanilla game, but it is more than enough for the sheer beauty DEFCON is.
Background music also deserve the massive praise - it is simple, minimal, ambient, atmospheric, yet haunting. Haunting is the right word. It is a perfect setting for this game.
Hearing a distant, muffled cry of a woman somewhere in the background while the screen is coldly informing you that you have you just erased millions of lives is an experience no other game offers.
As for the gameplay, the most important thing, after all - do not be fooled by the looks of the game. It is a complex strategy title, a unique one in the bunch, which doesn't fall back behind any of its genre "collegues".
There are many ways to commit nuclear holocaust, many little details and tactical manuveurs to be had - I admit myself that I'm still quite an unskilled player, but seeing the ways I was eradicated of the map and reading several walkthroughs, I can confrim - this game is truly a strategy game.
Only real flaw of the game is its community, or to be precise, the lack of it.
I had to wait for more than half an hour, sometimes, to fine an open spot in a game. Creating your own game can result in even more time spent.
However, there are still players, you just need to be a tad bit lucky.
In the end, I recommend this game - if you're interested in an unique experience, picking this up on a sale day is no wrong doing.