Please, sir, may I have some more?
Graphics: They are outstanding. Despite some walkthrough (bodies' going through walls and/or floors) they are great. The Hitman looks good, and with high enough graphics settings, you can actually see the numbers of the barcode imprinted on his head. The smoke effects from fire are good, and the world the Hitman operates in looks like a real world. Stuff flows with the wind, mirrors cast accurate reflections, water reacts realistically to your walking, walls look good with no sign of jaggies (usually on edges of objects which look like stairs), and overall good quality.
Presentation: The game is presented great. It has a fairly easy learning curve, lots of missions that aren't repetitive, a good selection of real-world weapons (no alien shrinkray here), stealth and action combined in a seamless transition.
Controls: Excellent. Hitman responds accurately to your input and without delay. Moving is as simple as pressing a key and using your mouse. Inventory, binoculars, sniper scope...everything is easily reached from the regular "WASD" setup.
Atmosphere: Creepy, yet real. Walk too close to a person and they will track your movements with their head, giving you a sense of being watched. This actually has some value, because if you kill someone or pull out a gun, they will always recognize you, even if you change your clothes. Speaking of clothes, when you kill someone, you have the opportunity to change into their clothes, thereby allowing you to blend it, which lets you walk around with more freedom.
Physics: Hitman has a great physics engine. Kill a guy sitting on a chair, and his body will slump over in the chair, just like you'd expect it to. Kill someone on top of a staircase and they will tumble down the stairs, laying correctly on top of the bottom steps and floor. In most games, you'd expect the body to just lay flat; well, not here. Here's another great example. You're dragging a body to a sewer grate to dispose of it. Let the body sit on the side of the grate with one leg hanging over the opening. The physics engine, combined with the weight engine, will let the body gradually seep into the opening until most of it's mass (depending on the bodyfat of the victim) gives and drops the body into the grate. It is amazing and must be seen to fully understand it's addition to the game.
Almost nothing. The camera is awful, and tracks you in a over-the-top, third-person perspective. Not that there's anything wrong with that camera position (Tomb Raider anyone?), but it just doesn't suit the game.
The Bottom Line
The first game in the so-called "murder simulation" genre, Hitman: Codename 47 is an excellent game well worth your cash. It'll satisfy all your needs.