Darkest of Days takes historical battles, and spices them up with weapons of the future. Imagine the Battle of Little Bighorn, with the weaponry from Halo.
The story is time traveling nonsense, but enjoyable none the less. You are fighting alongside General Custer, wounded, when all of a sudden the fabric of time is ruptured, and an agent from the future saves you, and takes you to their time. Here, you are told of a missing time traveler, who is suspected of tampering with historical events. You are trained, and sent back to famous battles to put things right.
Graphically, Darkest of Days does look a little old fashioned, but acceptable. The animation of talking faces is pretty basic, and close up the textures aren't too pretty. The sound is good, although some of the voice acting is a bit odd. The gameplay is a strange mix of traditional first person shooter (FPS), and "on rails" shooter. The levels in the demo are highly scripted, so there's not much you can do except what you are told to - just make sure you don't die.
The different weaponry available really change the gameplay too, and the experience of using a futuristic machine gun against a US civil war age army is undoubtedly cool!
Darkest of Days is a quirky FPS, but has some great moments in it, and the lengthy demo is definitely worth playing through.