The Darkness doesn't really try to shake things up, but it's good at what it does.
Aside from the awesome story sequences, the only thing that really differentiates this game from other shooters is the Darkness powers. You unlock the powers at certain key points in the game, which is good in that it allows you to become comfortable with the way that each power handles, but it seems odd that you can't use all of the powers as soon as you transform into the Darkness. In the cutscene in which you transform into the Darkness, Jackie uses every single darkness power, but after watching him do all of that cool stuff the game limits you to summoning darklings and using the creeping dark power until you unlock the rest. The Darkness powers add some much-needed variety to this otherwise by the books shooter. The guns in the game don't pack the punch that they should. The dual pistols that Jackie weilds from the first level onwards are more powerful than any other weapon i've encountered so far, possible with the exception of the dual SMGs. This is also one of the only games in which the auto aim is really noticable to me. It seems to gravitate towards all light sources and the heads of enemies. Other than the shooting aspect, the game is really good. The graphics are excellent. This is a level of detail rarely seen in games, even on the next gen systems. The music and voiceovers are equally good. The darkling minions are hilarious. They are a stream of one-liners, saying things like "Rest in peace" as they urinate on your deceased enemies. The outfits for the darklings are also fun. Replay value is added by collectibles, which let you hear some pretty funny telephone messages and letters by using phones and mailboxes. In conclusion, the Darkness occasionally falters in gameplay and variety, but it always succeeds in story and atmosphere. (And trust me, the game lives up to its name. It's dark.)