IMPRESIONES:
FFXIII is a really interesting game. No doubt it is the HD successor to the FFX/FFX-2 school of design in terms of many things, but what is surprising is that it doesn't really throw away the concepts pushed forward by FFXII. At the same time, the game itself is a whole new beast. There has never been a FF like this before, and it is a very bold new step for the series. Some fans will almost certainly like it more than others, depending on what your stake in the series is, and what is important to you in a RPG. Either way, I think it is very refreshing to have a game which breaks down barriers while erecting other new boundaries in defining what constitutes a "Final Fantasy" mainline game.
The first thing I noticed about the game was how uncompromising it was in letting the narrative dictate the entire direction of the game. Right from the start, the game starts with a bang. There has never been a FF game or a RPG as cinematic driven as FFXIII. I don't mean it uses a ton of cutscenes (lots of games do) during the game, but rather the entire experience feels like you are playing a part in a film instead of a game which uses a lot of cinematic sequences to tell the story. The best comparison would be with action games, where not only are the levels linear, but everything is designed around the narrative itself which you play through. The game doesn't consider the player's needs or wants in relation to what they want out of a RPG, but instead strives to deliver a very specific experience.
Now that could be pretty bad if the story and characters are terrible and no one cares. Thankfully, I think this is one of the strongest FF games in terms of narrative and characters. It's definitely up there with FFVI. The style of the scenario is such that the player is thrown into the world at a crucial period, and experiences several events unfold which don't quite make complete sense immediately. The game also throws the characters all out at once, without wasting time with detailed introductions or the standard form of character building.
Instead, you learn what each character is like and what they're each about as you play, and as you see them react to situations and discuss their own desires, fears, dreams and experiences. Much of what they have done in the days leading up to the game are vital to developing their characteristics and for the player to understand them, and these events are slowly unraveled through flashbacks as you play the game. This method of narrative means the game pretty much never slows down. The characters are always on the move, and with their lives all in peril there is no time to waste. Yet it also allows the game to slow down for some short moments along the way to build up on the characters and to let their various layers unfold.
All in all the narrative is very strong, the characters are extremely likable, and the plot keeps pushing players forward with the motivation to learn more about everything - the world, the characters, and the crux of what is happening in the world that allowed the events at the start of the game to occur. The sense of mystery is a high point of the storyline, and definitely a driving force for players to keep playing.
Gameplay-wise, the game is also very different from anything before. The battles are faster than ever before, but also more different than ever before. The Optima system is often mistaken for a sort of Job system, and a passive option in battles which allow you to change your Roles. It couldn't be further from the truth. The Optima system is in fact simply another way to input commands.
Because of the speed of the battles, even if the game gave the player the option of inputting commands for each character separately, and toggling using L1/R1, it would be unplayable. No human player would be able to keep up with the battles and to select AND input commands for different characters at the same time.
What the Optima and Role system does is to define 6 very specific type of roles, and limit what each role can do down to their core usage. Hence by changing the Optima of the party in battle, you are essentially specifically changing the commands each party member can make, and hence giving them near-specific orders until you change the Optima again. It is not a passive command, it is something you will have to use in almost every battle.
The game is NOT being played by "AI" so much as command input being aided by AI, and instructed by the player. Due to how battles are designed, and what the player is required to do to win battles, the emphasis is still on strategy and tactics determined by the player. Anyone who claims that the AI party members in the game are "auto play", is probably a person who has previously complained that the Gambit system is "auto play" and so we can know to safely ignore them.
Outside of the battle system, the game actually features some pretty interesting forms of character customization. Gone are character levels, just like in FFX. Instead, in it's place are various systems which break the core meaning of "leveling up" down into different bite pieces to make the player more proactive in considering how to strengthen any given character. Each character starts off with access to a limited selection of Roles. Each character's Crystarium (think simplified Sphere Grid or License Board) for each Role is different. So even between say Lightning as a Blaster and Snow as a Blaster, the abilities they can learn and the stat boosts they can gain from putting in CP is different.
Aside from stats and abilities gained from Crystarium, the game also features a pretty interesting Weapon and Accessory system. Fans of weapons will be happy to learn that unlike FFX, the weapons in FFXIII have stats again. Each weapon has a Physical Attack and Magical Attack stat, and some weapons have an ability attached. Weapons also have levels, which starts at level 1. Using materials gained from defeating enemies, you can pump them into weapons to give the weapon experience, and level it up. Each weapon has a different sort of balance for the stats, so leveling up the initial weapon is just as viable as changing to a new weapon each time you can buy or find a better one, and leveling that up for a little bit before the next one.
In some cases, specializing on a certain weapon and leveling it up over and over might be a much better option, depending on how you plan on using the character it's equipped on. Different weapons gain different amounts of exp from different materials, and using a bunch of materials which give a small bit of exp might sometimes trigger an exp bonus chain for the next set of materials you put in. There's a bit a experimentation involved, although with how limited some materials are earlier in the game, it might be wise not to waste too many on trial on error too soon.
Accessories also have levels, and each accessory has an ability tied to it. By leveling it up, you increase the effectiveness of the accessory. For example, a Silver Bangle Lvl1 would give HP+100, and putting in enough materials to get it to Lvl2 will change it to HP+116 instead. What I've also noticed is that there are synergy abilities as well. Hope had a weapon which had no abilities on its own, but when equipped with that weapon AND a certain accessory, it gave him an ability which boosted Physical damage. The ability is not listed on either accessory, and is essentially hidden. As such, it reasons that there are many more of this sort of secret combinations of weapon+accessory which when equipped grant bonuses.
Okay, I'm getting tired from writing too much now. If there are any questions I'll hang around for a while to answer them.