A lack of a strong story and characters make Nocturne weak in some areas but the games great combat is a saving grace.
Story & Characters
This is Nocturne's weakest point without a doubt, for me a great RPG needs a strong story, strong rememorable cast and lots of emotion. Unfortunately Nocturne lacks all of these, the story while complicated as a whole is dull and lifeless and the cast even your own playable demi-fiend are extremely unlikeable and instantly forgettable. The plot of the game focusses around an apocalypse hitting earth and a new demon infested world being reborn, (un)fortunately for you and a handful of other humans you survive this whole experience and with your new demonic body set out to help form this newborn world. On your quest you'll meet many others with the same thing in mind and your once friends will lose their humanity far quicker than your own character appears to. However other cast members aside, whats on the agenda here is world shaping and there are multiple conclusions to what happens in the plot depending on your choices in the game (I have watched them all on YouTube and I thought all were fairly weak). By the halfway point of the game I'd lost all interest in what was happening and was just yawning through cutscenes. It's a shame but a sad fact that this game really needed a good story to improve on itself and it seems to have just been ignored.
Gameplay
So without a good story Nocturne needs good gameplay to redeem itself and fortunately thats what it does have. The combat starts very simply punching away at enemies with your Demi-Fiend but you rapidly realize the depth of the fights and scale of the tactics you need to progress in the game. In Nocturne your team consists of your lead and three demons who you either recruit by talking to them in battle, or fuse two demons you already have together to create. Now there are many demons in the game all with different skills and to progress you need to succesfully employ the skills of demons you find and the skills of your demi-fiend to beat the games many bosses. Essentially boss fights are what this game is all about, each boss you come against will 90% kill you on the first few attempts until you the player formulate a strategy to beat it. At first this may sound frustrating (which it can be) but ultimately when you work out the solution to the boss battle it's so satisfying to progress.
As an example one of the games bosses "Trumpeter" casts a spell that heals the most injured person in combat to full health and another which kills the most injured person instantly. He alternates between these every four turns and if he is the weakest heals himself. To beat him the easiest thing to do is to have a weak demon (mine was Level 3 and my team was Level 50) and summon him just before the spells hit each round, so he always dies and always gets healed to full. This renders the bosses attacks useless leaving you to pound on him with your three high level party members. Once you work this out and successfully employ this strategy it's a great feelling and each and every boss works in a similar way. Sometimes even just equipping the right skills and immunities in combat can make an impossible battle winnable in just a few rounds.
That said sometimes the game can push the difficulty too far, ten attempts at a boss is reasonable, but fifty? The game can be annoying to say the least and in it's relentless quest to teach you that you suck at video games the fun can occasionally feel like its being overlooked.
When your not recruiting demons and fighting bosses in Nocturne you'll spend a fair amount of time solving puzzles and trekking across the world map. The puzzles while usually all simple and not frustrating can take a bit of time to work through occasionally and make a nice distraction from the endless and challenging combat. The world map is one of my personal pet hates of the game, for me at least I found it very hard to find my way about the game world often getting lost and wandering into the monotanous random encounters on the map. It just added to my frustration with the game at times but as I say the boss fights were so satisfying to beat I kept coming back for more.
Graphics & Sound
Very little to be said here, the game looks good for a PS2 title and in general I was impressed with it's crisp if a little bland game worlds. The models all look pretty good too and the stylised look of the cast worked well with the games setting. Unfortunately I thought the sound was pretty sucky, none of the tracks grabbed me and the lack of the cast speaking kinda detracted even more from their already hollow personalities.
Lastability
Well theres a lot to do here, to get to the final boss your looking at about 30 hours on your first playthrough and if you are a true masochist and want to do all the optional content and find every demon theres probably 100 hours here. Can't really argue with the value for money this game brings.
Overall
Nocturne can be very rewarding assuming you don't mind dying instantly from time and time and having more than a few attempts at some of the fights. It's the combat system that lets it shine and lack of a plot that holds it back. It is however something to try if you want a bit of a change from the usual model of JRPG and despite its flaws I recommend it.