Late Opinion: Great Combat, but Underwhelming Plot.
It's easy to complain about XIII's linearity, but harder to overlook the game's unique timing based combat that allows for players to literally air juggle their opponents.
One of the first things I noticed about Final Fantasy XIII was that opponent's had a lot of health. I did a lot of damage and their health bar never lowered all that much from my attacks. While games like Dead Space may have expertly removed the HUD (Head-Up Display) by placing key information on the player's avatar, Final Fantasy XIII's combat revels in the sheer amount of data it can display at one time.
Combat in Final Fantasy XIII is rooted in what fans have come to love. Job classes,enemy specific strategies, and character customization, but adds a level of alertness that previous entries can't really match. Battles are limited to 3 characters, only one of which is directly controllable. This is reminiscent of the decisive system used in the previous entry. While Final Fantasy XII introduced gambits, prioritizing the decisions your allies would make and allowing you to customize them, XIII eliminates that extra layer of complexity by making sure your allies always take the best course of action.
Don't be concerned by the lack of control. While you're controlling that one character, there is a lot to keep track of. In combat there are three spots your eyes will learn to watch very carefully, your character's health bar, your opponent's health bar, and your opponent's chain gauge which tells you how close your opponent is to being staggered. Once staggered your opponent may be susceptible to de-buffs and air juggling, while receiving significantly more damage from all of your attacks.
Since XIII's enemies act differently once staggered it's important to be able to change strategy on the fly. This is where Paradigms and Roles come into play. Roles are a new and fitting name for job classes. Once an AI controlled ally has been changed to a new role (job class) they'll do what you'd expect from them. If they become the medic role they keep the player well healed, if they've converted to Commando, they focus on attacking and so on. A paradigm is simply a delegation of roles on to your party members. For example, an enemy with high defense may require you to have all three characters focusing on filling the monster's chain gauge, once staggered, those characters may want to focus on dealing damage or de-buffing. At that point, the player can switch paradigms, which reassigns the roles their party members currently have, to roles that can fulfill those specific tasks.
Timing comes into play fairly often. You may want to switch your medic to a spell caster for example, but may consider it unwise until all your party members are healed. Since a character's active time bar must be filled before they can perform their abilities you'll often find yourself hovering your finger over the paradigm shift button until those green health numbers are visible, then quickly shifting paradigms to deal damage. This keeps the player alert and engaged to combat. Making even basic encounters more enjoyable then hitting confirm over the “Fight” option over and over again.
Combat is fun, quick, and at times puzzling when your entire party gets wiped from a new enemy requiring a new strategy. However, the game never gets frustrating because you can simply hit retry at the game over screen (with no consequence.) As a side effect, basic encounters can become more difficult then what you'd expect from a Final Fantasy. Which is a pleasant surprise.
While linearity may be a big issue to a lot of gamers, the real issue with XIII is the game's pacing. Since combat's HUD can appear so overwhelming to new players and observers I'm not too surprised that combat mechanics were introduced little by little, but denying the player from a full party for roughly half the game was a bit much. It leaves one feeling frustrated and almost insulted.
Fans of the series have always regarded the Final Fantasy games as having intricate character and combat customization options, but that's only ever been half the equation.
While XIII's universe is interesting and pans out well enough over the course of the entire adventure. You're never quite invited in. The game is littered with gorgeous cinemas, occasionally bombarding you with over the top action, but the game never takes advantage of it's story segments to organically explain concepts of Cocoon, Pulse or even your own party members. Within the game's main menu, is an encyclopedia that fills you in on the ins-and-outs of the universe. Getting regularly updated on your adventure you'll have to stop the flow of the game to catch up on some interesting information, but it's never essential.
Final Fantasy XIII is a solid experience that simply cut out too much. With a high development cost and a guinea pig to Square's Crystal Tool engine, XIII's vision ends up too specific. Half of the dungeons are narrow path ways leading the player from one encounter to the next, towns are non-existent and the side quests nothing more then rare monster hunting. All of this would be a bigger problem if the combat wasn't as much fun as it is. Plus those hunts are addictive.
Since the first half of the game keeps such a tight leash on all of your actions, including limiting your growth on the Crystarium, The Crystarium being XIII's version of X's Sphere Grid (A stat and skill tree, not to unlike what you've seen in Diablo 2.) The large open area of Gran Pulse in the 2nd half of the game is exciting to explore. You'll see enemies that look and act like what you'd expect from a universe with it's own ecosystem. Monsters that will dwarf you like any creature seen in Shadow of the Colossus. Not to mention new areas that open up as you complete monster hunts, making the whole area addictive to explore. Sadly indulging in any of this is optional. The game's narrative forces you onward.
At least there's no stress about one-hundred percenting the game when you get there. The game is extremely forgiving through and through. While other role-playing games this generation may require you to beat them 2 or 3 times to unlock secret items or ultimate weapons, nothing in XIII will force you to restart. While some things may be done more efficiently in certain ways, XIII lets you take on any additional objectives at any point. No items, at least towards Achievements, Trophies or side quests are skip-able.
While Final Fantasy XIII is a linear experience with a slow burn. The combat does become more engaging the further you progress. For those that love exploring towns, worlds, and completing optional sidequests, XIII may not seem like it has a lot to offer. But when you start exploring the larger world halfway though, the itch you've been wanting scratched is there. Combat is fun and air juggling foes is as crazy/neat as it sounds. Stick with it long enough and before you know it you've completed a 50 hour quest that leaves you anxious for more.