An amazing addition of creativity in plot and story to an equally creative series, using repetiition wisely.
While the story itself when compared to other DMC games isn't the cream of the crop, it is the voice acting of the game that will set itself apart from anything a player has heard in the series, or in the gaming universe for that matter. The diction, dialogue, and emotion, deserve fitting awards; every statement, cry, groan, etc, is felt by the player with immediate response. This is more than a mere game; this is a story with living, breathing characters, and is more than worth the play-through simply for the cutscenes.
Gameplay-wise, the action has been upped from Devil May Cry 3, and has also increased on the series' love of insanely chaotic combos and swordplay. A feature that was loved in DMC3, were the numerous styles that the player could choose to fight with, although it was criticized to to having to wait till the next mission, or finding specific points to change the style, weapons, etc. This has been completely atoned for in DMC4, as with a mere button press, players may cycle through all of Dante's original DMC3 styles, with the addition of another that is added on later.
Nero's addition to the play obviously is vital to the story, but it is the gameply that is equally affected. The "Devil Bringer" Nero possesses, brings new elements into the game ala Scorpion of Mortal Kombat.
Players will have to resist the urge to constantly snatch an enemy and reel them in before beating them to a pulp with the demonic fist, if they have any hope of achieving a high style rating for the mission, which is another feature guaranteed to keep gamers busy.
Flaw wise, the game possesses next to nothing that would detract from its success. The graphics are top notch, the cutscenes Oscar-worthy, and the action a pure adrenaline rush. The difficulty issue that plagued DMC3 has been addressed with a number of varying difficulty options, starting out with a much more relaxed-but in no way casual-difficulty than the games predecessor. Repetition, is the only main defect. While used as a plot device, the obligation to go back and fight the same bosses that a previous character did not finish off is a bit irritating, but fortunately, is more than made up for by the different character's extremely diverse skills.
All in all, the game is amazing, and extremely worth having if one is interested in an intriguing plot, the DMC series in general, or just unleashing absolute carnage.