Wolfenstein uses a modified form of the id Tech 4 engine, and it looks really good. However, it doesn't offer a good first impression. Before you upgrade your arsenal, all the action is represented relatively blandly. However, once you buy your first Big Bore and bayonet, the game becomes almost as much a joy to watch as it is to play. Bullets punch entrance and exit wounds in the flesh of your enemies, limbs fly, faces are rendered into unrecognizable red lumps, and gaping neck wounds will make you reach for your umbrella. Veil powers activate with an awesome effect that makes the entire environment burn away like a bit of dry parchment. Load screens are almost nonexistent, and the framerate is solid, though entering and exiting the Veil will cause it to stumble a bit. The animations are superb, as well. You won't often see an enemy die the same way twice.
Wolfenstein's audio quality is good on one side and bad on another. Even during the soft pieces, the music is always screaming "SERIOUS BUSINESS!" in your ear. This is fitting, since this game is about Nazis taking hold of supernatural powers -- which is about as serious as business could conceivably get. I found the voice acting quite bad, with the exception of B. J. Blazkowicz. Every German, friend or foe, speaks English in a ridiculous German accent. Every "th" sound is painstakingly and unnecessarily changed to a "z" sound. Hearing Nazis yell at each other in English makes absolutely no sense. However, I give major kudos to the developers for having some of the Nazis scream "Mein leben!" in the throes of death.