Duty Calls opens with these words:

War. War never changes. Or does it? War has changed. Did it? The answer is no. Unless it is yes. No, of course it is. It is war.

It takes longer to download the free PC title Duty Calls than it does to play it, but the joke is amazing. The game spends ten minutes or so mocking the conventions of modern, big-budget war games, while praising its own realism and leveling your character for nearly every enemy you kill.

One soldier points at you, tells you he's pointing at you, and says that this is very important. Then he gets run over. "Oh, I'm dead, increasing the drama of the story," he says mournfully.

But we won't ruin all the jokes, and you do get to look at that nice Bulletstorm trailer again once you finish the game's single mission. The content is slight for a 700MB+ download—sorry Canadians—but it's delicious to see a developer mock games that tend to take themselves so very seriously.

The premise is of course that gamers should enjoy a more funny, action-packed experience than we're used to from dour, "realistic" games, and having the player say the word "boring" while pulling the trigger on his gun makes the point... to an annoying degree.

Making fun of other games to help market them is a trick that Bulletstorm has already used to great effect, and we're hoping they keep it up. You can download the game at the Duty Calls website, and give it a play for yourself.