Redemption for the series.
Vergil himself has some nifty touches: carrying three melee weapons at once, having special ranged attacks, devil trigger from the beginning, and a new style. The Dark Slayer style works like the level three trickster style: you can blink off of the map to dodge an attack, teleport closer to an enemy, and at higher levels teleport upward or downward to get out of the way or finish up a combo before the style meter goes down.
Those are the good parts of the change: the full game is an entity in and of itself. Once you figure out the real way this game works, you're set. You are in for long rush of an action game that keeps going and going without stopping until something hits you. The enemies and bosses are challenging, and you are given weapons to meet the challenge. You receive in total: Rebellion (your starting sword), a pair of twin-swords, a set of tri-chucks, a set of gauntlets, and an electric guitar (I mean really electric). In addition, you have your handguns, a shotgun, rocket launcher, multi-targeting laser gun, and a sniper rifle. Every weapon has a strength and is visually stunning when used correctly. The styles take the gameplay to a new level, giving special emphasis to different important parts of the game. There are also a couple of special moves that are not keyed to the style button, but are accessible with specific styles or with any style (e.g. wild stomp, pole-swinging, million-stab, enemy-surfing). The first Devil May Cry pioneered the wall-walk/wall-jump as well as the style meter, both of which have become staples of most of the greatest action games since then. Devil May Cry 3 introduces the quick weapon switch and styles, which should be seen in many action games to come. Those of us who remember DMC 1 will be thankful to know that the plot (while transparent) is not as bad as it was in the first game. The characters are memorable and the voice acting is very good. The cutscenes are actually one of the highlights of the game and will have many an action fan laughing out loud at the sheer craziness of Dante's boldness.
If the first Devil May Cry was originally supposed to be a Resident Evil game and became DMC, this game was supposed to be a DMC 1 and became Devil May Cry 3. This is to say that the first game had a much more claustrophobic and dark atmosphere with scary enemies to make adrenaline come from fear, tension, and an action-rush. This game just focuses on the action. The music was haunting until an enemy showed up, in which case there was a loud guitar riff and the heavy metal was on. While the environments certainly have a dismal feel, there is not nearly as much attention paid to it, and the music is unnoticed until enemies show up, then it is focused much more on the metal.
While it's not quite the work of art that Devil May Cry was, Devil May Cry 3 Special Edition redeems the series and indeed itself with overhauled action and gameplay and establishes itself as one of the best action games on the market.