If this is Eidos' vision of reality, we should all be very worried.
The graphics are perhaps the high point of the game. The visuals are beautiful. The character models are nice and the environments can look nice at times, but they can also look like absolute garbage.
Sound isn't awful, with a small selection of licensed tracks from the Vietnam era included. However, most of the time you'll be listening to your squadmates yelling or the Viet Cong taunting you with the same two or three lines over and over. Honestly, I think I've heard someone yell "You go home in body bag, G.I." in a really bad Asian accent enough for one lifetime.
Controls are rather straightforward and pretty much the same as every other shooter for the X-Box. The thumbsticks feel a bit oversensitive, but at least you have the option of changing the sensitivity.
Gameplay is where Shellshock really drops the ball. Collision detection is horrible, the damage modeling is on par with a Wile E. Coyote cartoon, and the AI is just plain dumb. On countless occasions I've emptied clips into one Viet Cong, only to have him get up. Meanwhile, I may completely miss on, and wind up scoring a head shot. In other words, shooting in this game is really just "hit-or-miss" (pardon the pun). Dying isn't much of an issue either, as the enemy soldiers just either sit around taunting you most of the time. When they are shooting at you though, they're pretty good shots, so you'll probably find yourself pretty shot up at times. Most games would make you go and find a health pack, but Shellshock lets you just fall back behind some cover and regenerate health. Not only does this make the game way to easy, it really takes away the feeling that you could die at any moment.
Shellshock was touted as one of the most realistic shooters ever made. If this is Eidos' vision of reality, we should all be very worried. If you love blood and gore, you may want to give it a shot. For those looking for a more complete shooter, there's so much better out there.