The Civil War, Antietam, and an AR 55 assault rifle. One of these things does not belong with the others.

8monkeylabs and Phantom EFX have released a demo for Darkest of Days, a time traveling FPS which casts you as a survivor plucked from certain death in order to serve as an anonymous guardian of history thanks to advanced technology. Although history remembers you as a dead man making you prime material for recruitment, you’ll soon be on the front lines in defending the timestream from someone else’s idea of history.

The demo knows how to get things started with a bang and the engine wasn’t kidding about boasting about filling the screen with lots and lots of soldiers (i.e. targets) for you to fend off. It includes the intro battle in which you relive your final moments at Custer’s Last Stand, a training level, and a jump to the Battle of Antietam during the Civil War to save someone who shouldn’t be in the fight.

And because you’re working for a highly advanced group of time travelers, you might also have to take care of things the old fashioned way: with superior firepower…such as an assault rifle for breaking through Confederate lines…

Oh yes.

By the way, that circle thing that winds up around the reticle and the green block? That’s the game’s version of “active reload”. By hitting the reload button as the bar passes through the green area, you finish reloading your weapon much faster. It varies depending on what you have, but in the case of the Springfield rifle, it cut roughly 2/3s of the time needed to get it ready for another shot.

But along with that awesome moment, the demo also has a few iffy things…some of the voice acting is a little bland and there are some invisible walls that are a bit too obvious…but the overall atmosphere in staging a big battle piece if great stuff. That, and this is only a small piece of a game that will take you from Antietam to Pompeii to WW2. The game is due out for both the PC and the Xbox 360 in September.