In a nice twist, your main opponent in the game won't always be some guy with a gun, but any streetlamps or bright lights that will send your Darkness powers receding in fear. I found myself having to reload quite a few times because I didn't pay enough attention to my environment, and ended up getting caught out in the open. It's a nice mechanic that gives a good sense of vulnerability and helps prevent each fight from feeling like it's a boring, straightforward "See enemy, kill enemy" formula. Paying attention to where the light is gets even more important once Brotherhood enemies start wielding high-powered flashlights themselves, leaving you with just your trusty shotgun to defend yourself.
By eviscerating your foes, eating their hearts, or finding Darkness relics hidden in each level, you'll also gain Essence, which is used to buy special Talents for Jackie. As your opponents get tougher and more resistant to your darkness powers, choosing your Talents adds a nice layer of strategic thinking to how you compliment your style of play. The Talents help boost your abilities, focusing on improving one area of combat by letting you perform different kinds of bonus-granting executions, overcharge your weapons, release swarms of demonic flies and the like.
There's quite a few to choose from, and on your first run through you'll probably only pick up about half of them or so. If you're a gun-happy fellow and prefer shooting your way around, you might want to focus on getting more ammo and explosive bullets, or if you're a fan of using the Darkness, you'll drop points on special powers that boost your toughness whenever you're in the shadows or add sharp blades to your arms for use in melee. Some you'll probably end up using more often than others. For example, I never really needed to summon a personal "Darkness" shield more than once or twice and usually only did it so I had something to throw at people.
The biggest issue with The Darkness II is frankly, it understays its welcome, and starts to lose some of the steam gathered up in the game's opening by being too short. You'll probably be able to beat the game in just under 6 hours of regular playing on the normal difficulty with a fair amount of exploring. And since a good chunk of the game is spent on story points like the "Is it real or not?" mental hospital and occasional visits to your mansion, some may find it to be a downer for things to wrap up so abruptly, especially after tense mini-boss fights and brutal gunfights. And not to get heavily into spoilers, but The Darkness II's sequel/DLC-hook of an ending was one of the most frustrating things I've encountered in a game in a long while.
There is a co-op Vendetta mode, which lets you pick from one of four assassins with their own Darkness powers to take on various side missions to kill off rival mob/Brotherhood targets, either by yourself or with a few friends. The Vendetta missions are a nice touch, add on to the main game and are a decent challenge, but I would've preferred to have a few more hours with the game's single-player campaign instead.
I wanted to like The Darkness II. I had a ton of fun massacring my way through my enemies and experiencing the intriguing story, but I was pretty disappointed that as soon as things got rolling, well, it ended.
Bottom Line: The Darkness II is fun while it lasts, but sadly doesn't last very long.
Recommendation: If you're looking for a pretty unique action game with a decent plot, The Darkness II delivers, but don't really expect anything substantial.
This review was based off the Xbox 360 version of the game.