When Square Enix rereleased Final Fantasy X-2, they decided they needed to beef it up a bit. Maybe they realized what I did, that they had a really good combat system, except the difficulty was a little lacking. Maybe they just wanted to add something new... or maybe they just wanted you to be able to fight as a chocobo or tonberry... well whatever the reason, they added the Creature Creator which works in conjunction with the main game. This addition substantially changes the gameplay, but is it for the better, or the worse, and does it maybe make this into a game that should be played by the Final Fantasy masses.
As far as story goes... well, there's not much. Shinra has created a system in which he can trap certain fiends and store them. You can then train them and fight with them. As you train them you learn more about their stories, and if you raise them enough you can get cutscenes showing what happens to the fiends after you release them back into the wilds of Spira. Since there's REALLY not much of a plot, and really, its not the biggest spoiler ever... I'm going to spoil the ending of the plot here, since it will be important later on in the review. It is revealed at the end of the game, that Shinra created this system because his mother was killed and believes she is a fiend, and thus would like to find her.
On to the game mechanics. You first must catch fiends. You do this by placing traps in different areas in a way that is very similar to using the airship. There are four different types of traps. Small, Medium, Large, and Species. The size of the trap corresponds to the size of the monster you'll catch, and species lets you try for a specific type of monster. The list of possible monsters you can catch depends on a few things. Mostly, it is based on the Chapter you are in, but finishing certain monster's stories or certain game events can also lock or unlock certain monsters.
Once you catch a monster, it is time to train it up. You can either keep it for your battle team or train it up and release it to see its story. If you want to see its story you must have it gain 4 story levels. A monster can gain a story level by either having it gain an experience level or through having it win a tournament or when you finish certain events in the main game. You can fight with your monsters in a few different ways. You can have it join your team in the main game by replacing Yuna, Rikku, or Paine. You can have it enter a tournament or you can enter the Battle Simulator.
I'd like to talk a little more about having your monster join your main team. In fact, in any of the above mentioned modes, you can actually use any battle party, including Yuna, Rikku, and Paine. So, literally its like adding party members. Monsters you catch fight differently, though, and I'll get into that shortly. When you place a monster into your fighting party, its size is very relevant. A small monster is the same size as one of your main members and takes up 1 slot in your party. A medium monster will take up 2 slots in your party, and so can only have a small monster or one of the girls along with it. A large monster fights alone as it takes up all 3 slots in your party.
The main difference in fighting with a monster instead of one of the girls is you don't have direct control over it. Each monster has an AI, that actually changes depending on how much you use it. A monster can learn different abilities, and chooses one to learn on each of its turns. As with any memberof your party, it can be equipped with a Garment Grid, Dressphere, and two accessories. These can sometimes have different effects on monsters than with your main members usually giving them additional abilities. In addition to any abilities learned from equipped items, a monster can learn 4 active abilities and 4 passive abilities. They can learn these either from having certain abilities used ON them, or by feeding items to them. Feeding items to them can ALSO give monsters PERMANENT stat boosts. So yes, you can train your monsters to really be infinitely stronger than Yuna, Rikku, and Paine.
Now, I said before you can't control what you're monsters do in battle. This is not entirely true. When fighting with caught monsters, you get a bar at the top of your screens that contains 5 stars. The more stars you have in this bar, the more damage your monsters will deal, the more they will take and the more likely they will use offensive abilities. Conversely, the less stars in the bar, the less damage they will deal, the less damage they will take and the more likely they will use support abilities.
Now, there may not be a plot to the creature creaotor, but there certainly is a progression to the game. This is mostly found in progressing through the tournaments of the game. There are a total of 10 tournaments in the game. Each tournament has you progressing through a single elimination bracket against different named preset teams. Winning a tournament gets you new traps to use to catch monsters, as well as one of a list of preset items, generally accessories that can be used to improve your monsters. The challenge in these rises very very quickly. You unlock new tournaments by either winning the previous tournament a set number of times or through catching and seeing the stories of certain monsters.
To train your monsters, you are going to be spending most of the time in the Battle Simulator. This is a room where you can fight against any of the preset teams that you have faced previously in a tournament. You can fight them over and over again without limit. This makes it incredibly easy to gain levels or to fight certain monsters if you want to steal something from it or get a certain drop or anything like that. It makes farming incredibly easy and really makes alot of these functions in the main game kind of useless since it is SO much easier to farm them here. Not EVERY monster is available in some capacity in the Battle Simulator, but most are.
Since a large portion of this game can be played while you are still in Chapter 1 of the main game, you can also unlock certain items that are VERY powerful for the early part of the game, and really remove any challenge from it if you are willing to work on levelling and improving your monsters to the point that they can win some of the middle difficulty tournaments. While this is not easy, you really can trivialize the main game very early on by putting some effort in here.
Now, while you can trivialize the main game, in no way can you trivialize the progression through the Creature Creator. The end game here is VERY difficult. Let's go over the different levels of difficulty you find here. You begin by going through the Standard tournament which you can farm easily with very little training. Beat this a few times and you unlock Standard Cup: Hard. This is a small step up, but again, just by training some experience levels, you should be okay. Grand cup is next, and here, already you are going to start fighting some monsters which are not found until Chapter 5 of the main game. Here, you are already going to need to learn how to balance your party properly and start optimizing your damage output. You're really still just focused on offense, however.
The first real brick wall of the game comes in the fourth tournament, Grand Cup: Hard. Here, you will eventually unlock Tonberry the Ripper, a Mega Tonberry. He will basically one-shor any of your characters until they have really high defense, a lot of hp, and probably auto-protect. It is now you really have to start training your monsters pretty high, and even then its a crap shoot if you're going to kill him. You get through this fight, and you really earn your way into the next phase of the game.
The next tournament, and the final one you can get to in Chapter 1 of the main game is the Youth League Cup. You can win some incredibly awesome items here, but to do it, you'll have to get through some really really hard fights. All the enemies here have a LOT of HP, so your offensive stats have to be insane. The hardest fight here at the start is Nooj. He has an attack called Lightfall which will hit everyone for a flat 5000 HP. Now, you probably have a lot of HP if you got through Tonberry the Ripper, but it is FINALLY here, that you need to learn how to properly control your monsters to be able to heal properly.
Once you beat the Youth League Cup a few times, a new team will appear. Ex-Crimson Squad. This fight pits you against Baralai, Nooj, and Gippal all at once. This fight will make you want to tear you hair out. The increased damage output, and pure length of this fight makes it insane. You will have to endure multiple lightfalls, possibly loss of MP, and just a ton of other damage.
As you get further into the game you can recruit different monsters. The next two tournaments require you use specific monsters to participate. These are the chocobo cup and the cactuar cup. Honestly, these are MUCH easier than the Youth League Cup and I guess just a different place for you to fight as you progress through the main game, not much to say here.
As you catch and release certain monsters as you go through the game, you'll find some monsters that don't have tales. In fact they'll tell you that they possess a fragment of a fayth. When you release them you gain the ability to fight Dark Aeons in the Battle Simulator. Now, these are the Dark Aeons you fight in the main story of X-2. Not the Dark Aeons from FF X... unfortunately... but still. If you find all of them and release all of the Fayth Fragments you unlock the Aeon Cup. Again, and disappointingly... still not as hard as the Youth League Cup.
The next cup, the Fiend Cup is unlocked by going through a long string of monsters that you have to catch and release, which then unlocks the next monster, which you have to catch and release a total of 8 times. At the end of the fiend cup, you either can choose to receive Omega Weapon or Ultima Weapon to train. If you choose Omega Weapon and release him, you find out he was the king of the fiend world and by releasing him the Fiend world will become unstable. Shinra then merges with the spirit of Omega weapon to become Almighty Shinra, whom you then must defeat. This is decently hard... probably could be harder though.
When you have beaten all the tournaments once, the last tournament unlocks. The Farplane cup. Here you fight a lot of special enemies. Also, this contains some of the hardest fights in the entire game. These include Concherer and Trema, a copy from Via Infinito. Paragon, who is a harder version of the one in Via Infinito, and the last enemy... Major Numerus. This is truly an EPIC end boss, who has all the difficulty you could ever want and is nearly IMPOSSIBLE if you use Yuna, Rikku, and Paine. Beating him gives you some of the most insane accessories ever as well as giving you ULTIMATE bragging rights.
Now, the game tracks all the monsters you catch and release, and if you manage to find all of them... including ones that can only be obtained in a new game +, you will find the last entry in the bestiary automatically filled by Shinra. If you select him you can view a special ending including the spoilers I mentioned above. This is very useful since it gives you the ability to make a new start point for New Game + at any point in the game. Now, what REALLY REALLY stinks about this, is once you get it you can NEVER see the bonus Zanarkand scene for getting 100% in the main story again. Somehow it was decided, that the Shinra bonus scene is a "better" bonus scene than the Zanarkand scene. This REALLY bothers me...
That said, this addition to X-2 is completely awesome. It gives you all the challenge you could ever want. It is really fun training the monsters you catch and figuring out all the strategies you need to. Getting through the brick wall fights in the game makes you feel incredibly accomplished, and even once you get really good with your abilities and everything, there is always Major Numerus if you want a challenge. I probably spent as much time in here as I did in the main game itself in my playthrough. I highly recommend going through this entire part of the game... though maybe leave a few monsters uncaught so you can properly see the Zanarkand ending.