Aaron1375 made some good points, so I probably shouldn't repeat them, but I will anyways, alongside adding my own. The first of which is that there is nothing bad I can say about this game, even in the face of complaints and comments like, "It's too hard!" and "You must be a masochist." (The latter may actually be true for about half of those who enjoy this game, because Nocturne is one of the most sadistic games you will ever play.)
First off, "a tad different" for a role-playing game, even a Japanese-made one, is an understatement. Shortly after the game starts and you're running around Japan, you're thrust straight into the end of the world, the Conception. With the help of an obviously demonic blonde-haired little boy, you've been turned into a half-demon and referred to in the game as Demi-fiend through the power of a bug-like parasite called the Magatama. You, by getting the assistance of a myriad of demons (that you can even fuse to create more) and kicking the cans of many more, must decide the fate of the Vortex World you're stuck in through the Reason system, a semi-hidden mechanic that develops like a real personality as you play. In the American and European versions (referred to as Nocturne Maniax in Japan out of its 4-5 versions), you'll also get to meet Dante from the Devil May Cry series, and even recruit him into your team with the right events!
The game play is downright fun and challenging, even for a turn-based RPG; probably the total opposite of Final Fantasy where you can use whatever attack you want and win nearly every fight. Through the Press Turn battle system, you can either double your Press Turn count with the right move (for a maximum of TEN across just four teammates), or forfeit the entire team's turns with the wrong one. You'll acquire up to 25 different Magatama with a variety of abilities available, and hundreds of demons to have at your command (some of which haven't seen the variety of moves available from the Magatama). However, people have complaints about difficulty. Welp, maybe this'll give you a hint: there's no Easy mode, and even Normal mode can rip you apart on the first battle. You'd have to be a total idiot to make this happen, of course, but overall you can expect to die at least 50 times. Don't get discouraged if you die so much, though! This gives winning a vital battle an even greater joy, the hardest of which (out of the SIX different endings) has actually brought me a euphoria-like experience.
The graphic design is utterly amazing. No, it's not an advancement in any way, but it's how Kazuma Kaneko, the Creative Director, made it that makes it sweet. What's notable is the Demi-fiend himself, who manages to look nearly perfect despite just having a pair of shoes and shorts, glowing all-over tattoos, and a horn growing out of the back of his neck. Yes, he has glowing tattoos that fade in and out JUST RIGHT at every angle no matter where he is. He looks pretty weak because of his lanky limbs, but the way he moves and the look in his eyes turns him into a subtle, yet total beast. Now why be a high-pitched sword-slinger like Link when you can be the most powerful half-human destined to rebirth the world? Now onto what I've actually just left my controller standing without input for: the music. There is absolutely nothing NOT impressive about the music. Paying even the slightest attention to what seems like a hundred different full battle and location themes may make you want to get up and dance, because all of them totally rock.
Sadly, IMDb limits prevent me from expanding further on an even more awesome piece of the game that was only added in Maniax and the international releases and practically makes up a good half of the game's experience (along with the 6th ending): the Labyrinth of Amala, so I'll finish it off with one more compliment: Demon Negotiation. This alone should imply that you'll be using diplomacy to work with demons. You will. They can ask you for money, items, or even to drain some of your life force, alongside even philosophical questions, but even after all of this, they may just heal you or outright LEAVE THE FIGHT WITHOUT GIVING YOU ANYTHING. They may even stop a fight to talk to you of their own volition and join your party! This one mechanic gives Nocturne a degree of realism I think no other game has done at the time, if ever, because even the exact same breed of demon can have completely different results for the same negotiating terms.
That's about it, so thanks for bearing with me here.
