I completed the original Devil May Cry twice and actually played through Devil May Cry 3 six times (twice on the original release, four times on the Greatest Hits special edition). As for Devil May Cry 2, I played through Dante's story, then gave up early in Lucia's side, because the gameplay was just too horrible. So it would seem that the series has had a checkered history, but with definitely more good than bad, DMC1 and DMC3 both being among my favorite PS2 games. In fact, to make things simpler, if at any point I refer to "previous installments" in a remotely flattering context, let it be understood that I mean DMC1 and DMC3 (and DMC3:SE). So, how does DMC4 stack up? After finishing it yesterday, I would say it is a worthy addition indeed.
Leading up to the game's release, much was made of Capcom's decision to replace Dante as the lead with a new character named Nero, drawing immediate comparisons to the unpopular Raiden situation in Metal Gear Solid 2: Sons of Liberty. Although Capcom mitigated the backlash by publicizing this move far in advance rather than deliberately deceiving players, fans still felt understandably attached to Dante as the franchise's main man. To a small extent, the MGS2 comparison is justified, as the game's story clearly means to contrast the brash, young Nero with the unflappable Dante, who actually seems cooler than ever as a result, making fans that much more eager to play as him instead.
In gameplay terms, however, I found Nero to be more than Dante's equal. While he has only one sword and one handgun, versus the many melee and ranged weapons that Dante has always had, Nero comes with two brand new mechanisms. The less significant of the two is the "Exceed" system, which allows Nero to charge up his sword to perform flashier, more powerful attacks. In practice, use of it is not at all necessary to succeed, and it's actually kind of tricky to find opportunities for charging the sword, but, at expert levels, it can make for extremely stylish combos.
The real key to Nero's game is his demonic right arm, the "Devil Bringer," probably the most significant addition ever to the franchise's now familiar combat dynamic. It's not a revolution, but it does add a legitimate third element to the signature sword+guns gameplay, allowing for more elaborate combos than ever before. You can knock the enemy away with the sword, shoot them before reeling them back in with the Devil Bringer, perform a ground combo leading into a rising slash to lift them airborne, follow with a midair sword combo, toss them back to the ground, shoot them several times during your own descent, then finish finally by crashing down on them with the sword. This honestly never gets old.
The Devil Bringer's awesomeness shines through even more so against bosses, as using it triggers a spectacular enemy-specific mini-cutscene. Despite it being non-interactive, I can think of few moments in gaming more viscerally-satisfying than watching Nero unleash a vicious combination of body blows against the evil pope.
Outside of combat, the Devil Bringer also adds a bit to platforming via the inclusion of some preset Bionic Commando-style grappling sections. While not a major part of the game, they are preferable to the clumsy bits of jump-based platforming that have always been a minor irritation in the series.
When the game eventually does switch over to Dante's perspective, it feels like a step back, despite the fact that Dante himself has more options than before. While he has fewer weapons overall than in DMC3, he now has access to all of them at all times and can even switch on-the-fly between his four fighting styles. This gives him about four times the number of moves that Nero has, but he has no equivalent to the Devil Bringer. With no way to reel enemies in, Dante has to waste a lot of time chasing guys down. Boss fights are also far less dramatic without the spontaneous mid-fight cutscenes. In essence, playing with Dante feels just the same as in previous installments, which isn't a bad thing. But Nero's game is an actual evolution that represents the direction the series ought to be taking.
(Funny anecdote: After several stages as Dante, I had become so accustomed to using him again that, when the game later shifted back to Nero, and I found myself facing a boss that was impervious to my sword and gun, it didn't even occur to me that I had a third option. This was despite the fact that, in the cutscene preceding, Nero had explicitly stated his intention to use the Devil Bringer. What can I say? I act on instinct, not instruction.)
One of the things the series has been known for is its high degree of difficulty, which has at times limited its audience. DMC3, in particular, was notorious for being insanely difficult even on easy mode, though DMC1 is just as hard, in my opinion. DMC4, on the other hand, is a much more approachable affair, more along the lines of DMC3:SE, whose generous continue system (free continues at checkpoints, with consumable Gold Orbs acting as extra lives) it retains. "Human" mode (i.e. easy difficulty) is a very leisurely experience, while "Devil Hunter" (i.e. normal) is challenging but never unfair.
Enemy variety is much improved over DMC3, with foes being a good mix of that game's glorified sandbags and some actual threats that require more thoughtful approaches, though there is nothing so dangerous as the exploding dogs of DMC1. The bosses, always a highlight of the series, are typical but well-crafted designs that are nowhere near as unforgiving as in DMC3, and the free continues help to relieve any frustration from dying.
Story has never been the focus of the series, but I'll mention that it is well-paced and unobtrusive, and, like previous installments, it's actually more compelling than it gets credit for, thanks to a charismatic cast backed by strong performances.
Boasting high production values and still by far the deepest, most gratifying combo system in the genre, DMC4 proves to be an extremely solid title with few peers in its field. It's by no means an innovative title, but the action is as addictive as ever and, for new fans, it's the most accessible installment yet.