A refreshingly fun, satisfyingly gory, pleasantly bad-ass shooter that helps keep the genre alive.
As far as the game itself goes, it starts out slow and admittedly a bit clunky when you are your mere mortal self. Quickly, you are shown all the incarnations of the Darkness' power in one life-saving display and are ready to go unlock the rest of the powers once the smoke clears. While the darkness powers are not seamlessly integrated into the game, they do make it a lot more fun (the most noticeable problem is that enemies will all but ignore Creeping Dark even while you are biting the faces off of and ripping the hearts out of people who are literally a foot in front of them). What really makes darkness powers fun is the demon arm (the second power unlocked) because it really lets you feel like you are in control of an awesome power as you effortlessly put out lights, manipulate objects, and impale enemies.
In comparison to the darkness powers, the guns seem mundane especially when you've unlocked all the powers and you are a one-man tentacle army. To counter this, the folks at Starbreeze gave long cool-down times to counter the awesome power of the darkness and reward you for resorting to normal guns by giving you excecution moves. These are akin to the melee counter attacks used in the Chronicles of Riddick and produce the same effect: you don't waste ammo, the other guy dies in gory eye-candy.
Last on the list of enemy-killing tools are the darklings. There are four kinds, but they don't last long enough or act quickly enough to be much use, especially at later levels. Don't get me wrong, they're funny, but they are not very functional. Compared to your body count (hundreds by the end of the game), it will take some trying to get each kind of darkling to kill more than ten enemies in the course of the game.
As far as graphics go, the game looks really good, and should be played in HD at all costs. It's almost a shame that you need to be in the dark so much, because the coolest thing in the game is to look at the serpent heads that make up your HUD in the light, when they glisten and you can see their excellent textures.
All in all, the darkness is a wonderful game with a great story, cool action, and the best looking HUD that I've ever seen. It doesn't really deliver as a horror game so much, but as an action game it delivers on every front. The only complaint I have is that the AI is lacking. Oh yeah, did I mention that YOU EAT THE HEARTS of your enemies? The darkness if full of moments where you will be wishing that you could take a third person perspective (e.g. an enemy takes cover behind a car, so you lift it up and use it to crush him against a house, or while you are training your sights on one enemy, you're also eating the heart of his fallen comrade, or you can talk to a hobo and continually flash darkness mode (serpents and all without him doing a thing)).