This mock weapons training video for 8monkey labs' time-travelling FPS Darkest of Days is as entertaining as it is informative.
Darkest of Days will have PC and Xbox 360 owners hopping all over time this September, so it makes sense to bone up on some of the historically accurate and futuristically exotic weapons you'll have at your disposal. It's nice to see a musket in a first-person shooter, though that reload time must be a real bitch. I particularly love the bullet point for the shotgun, which pretty much sums up my feelings about shotguns in shooters since time began.