Well, XII is reminiscent of many, many things. Vagrant Story (unsurprising as the score is by the same composer), Star Wars (for the world it's set in) and Phantasy Star IV (for the hunts). At the time of writing this I'm about 50 hours into it.
Story
Weird, because it's pretty big and also quite rubbish. The story of the world itself, (Ivalice), is a bit generic (big empires, political intrigue etc) but I quite liked it. There's even talk of empire, bounty hunters etc. Very Boba Fett meets Darth Vader.
However, the story about the six main characters is pretty uninvolving. Balthier's quite interesting, Fran and Basch get a little character development, Ashe seems rather 2D. Vaan and Penelo alternate between being irrelevant and irritating and seem to have no real reason for being in the story at all.
The plot of XII is about the world, and the characters, whilst linked to that, aren't actually central to it. Vaan and Ashe are Tidus and Yuna lookalikes (thankfully without Tidus' godawful voiceover 'artist'). The story is slowly paced for a long while and not involving for much of the time. However, there are one or two plot twists that are genuinely interesting.
7/10
Gameplay
For me, the best part of the game. Totally different to any other rpg I've played.
Instead of the traditional turn-based or active time battle, combat is instead largely automatic. Of three party members (occasionally accompanied by a fourth uncontrollable and temporary character) you directly control only one. At any time you can open the menu and give orders to any of the 3 though. Through the use of gambits (very basic programmes, such as "Attack nearest enemy") your party will attack on its own accord. Gambits are ranked in terms of importance, so attacking can be interrupted with curing if someone's HP falls below a prescribed level.
A nice improvement is the lack of random battles. All enemies are now visible onscreen and on the minimap. Unfortunately, fleeing doesn't work so well as, irritatingly, enemies can attack and cast spells whilst running (unlike your party). However, this is a relatively minor gripe.
The gambit system means no more pressing attack relentlessly to kill a feeble monster and makes levelling up for less tedious. There are a maximum of 12 gambits per character, which is a reasonable amount.
Spells, armour, weapons and accessories are all buyable. If a spell is bought all those with the correct licence can use it. For any given object/spell to be usable you must first attain the licence. The licence board is a grid where you swap lp (licence points, 1 per defeated enemy) for the right to wield a weapon or learn black magic. It's far simpler than the ludicrously large sphere grid of X and things can be learnt pretty quickly.
Because of the gambits and the licence board (which is identical for everyone) all characters are highly customisable...perhaps too much so. It's very nice to be able to mould characters any way you like, but being totally adaptable does rob them rather of any uniqueness.
Another change is that monsters don't drop money, they drop loot. This can be sold at any shop in return for gil (money). You can also steal loot from monsters.
Overall, the system is very well-balanced. You'll never have enough money to totally refit your whole party every time new equipment becomes available, but you'll never be destitute either. Because MP can be restored slowly by walking, and more quickly if you learn certain licences, mages aren't actually crap. Spells are strong enough to be useful, and as mana is restored over time, a mage isn't useless after they run out of MP. Status effects like haste, protect etc last long enough to be worth having but not forever. The boss battles are actually challenging (then again, I'm almost always underlevelled:p) and battle is a real test, not a cakewalk.
9/10
Sound
The score was ok. When I heard it was the same guy who did Vagrant Story (the only rpg other than Shadow Hearts that consistently has good tunes throughout) I was pretty pleased. Sadly, VS this is not. Don't get me wrong, the music isn't rubbish, just... forgettable.
Sound effects are reasonable, nothing standout, good or bad. A pet hate of mine is that the armour sounds like wafer-thin aluminium when the judges and soldiers march about. Not like VS where it actually sounds heavy (and, as a chainmail hauberk weighs around 45kg, it is heavy indeed).
Voiceovers....largely bleh, again. Vaan has a mildly irritating voice, but it's not nearly so bad as Tidus. Balthier sounds like an American trying to have an English accent. It's also interesting that some of the empire's big guns seem to try and have ye olde English speakery.
7/10
Replayability
Not finished it yet, but I reckon this is pretty high.
The licence board allows for high degrees of character customisation (perhaps too high, but that's by the by). There's a large number of marks to hunt down, titles to collect in the Sky Pirates' Den etc etc. There are also a number of sidequests. They don't jump out and slap you in the face (other than hunting) but they are there, if you can find them.
9/10