One word of advice. This review should not be read if you do not like Final Fantasy XIII, or
if you do not have an open mind on how different this game is than previous Final Fantasy games.
If you are fine with it, read this review on.
Story
The story took place 3 years after the events of Final Fantasy XIII. After the fall of Cocoon, Cocoon residents have began migrating in Gran Pulse and start living there. As Serah dreamed about her sister, Lightning fighting with a man by the name of Caius, a meteorite strike at her town, New Bodhum. Numerous monsters attacked the town, and an unknown man called Noel saved Serah from the monsters. Noel came from the future, and was tasked by Lightning to bring Serah to her. Serah agreed, and together they journeyed to different timelines to find Lightning, while solving paradoxes in each timeline.
Storywise, this is much better than Final Fantasy XIII's storyline, but it can be confusing as there are many jumps between different timelines. Time travel is a very good concept to be used in a story, but it is very hard to be implemented in the plot to make a good story. Unfortunately, the storyline of this game is around the average, not too bad, not too great. Fortunately, the game does explain some important terms unlike in Final Fantasy XIII, which actually helps you to understand the storyline much better.
Character developments in the game are great, and I especially like Noel's development. His background story is a bit sad and emotional, and the best part is he is from the future. Other characters such as Serah and Caius also have great development in their characterisation in the game. Too bad we don't get to see much of the previous characters in the game, and most of them appear briefly in this game.
Gameplay
This game plays like Final Fantasy XIII, with some differences. First of all, you only have two playable characters in the game. That's right, only two, which is Serah and Noel. Your third party member spot is filled by a tamable monsters, which is gained by fighting them.
Unlike in Final Fantasy XIII, encounters are random, and they are triggered by moving around in areas. When they appear, there is a chance for you to strike them for Preemptive Strike, which allows you to strike them first.
The battle system is the same, with ATB gauge system needed for you to execute actions. You can choose Auto-Battle to have automatic commands being executed immediately, or manually type in your own commands. You can also use items to heal yourself, or change your Paradigm commands by using Paradigm Shift.
Staggering is back in the game. Most enemies have their own Stagger gauge (measured by percentage), and can be filled up by attacking them repeatedly. If you manage to maximise the gauge, the enemy will reach a Staggered state, and will take more damage to your attacks than usual. Be aware that the Stagger gauge will not stay up for long, and eventually will diminish if you let time pass and if you don't attack them quickly. Regular enemies have low Stagger point, whereas tough enemies such as rare monsters and bosses have higher Stagger point.
There is a new feature in the game called Wounding. Some enemies and most bosses have attacks that can cause Wound status, which reduces your maximum HP. For example, if that boss hits Serah with an attack that has Wound status, her maximum HP will be reduced permanently in battle from 600 to 550. Prolonging battles against enemies that has Wound attacks is not recommended, and it would be best if you defeat them quickly.
Unlike in the first game, you can now switch your Party Leader freely, while in the menu or battle. This time, if your leader dies, your other character in the game will become the Party Leader. Subsequently, if both Noel and Serah is dead in battle, you will get Game Over. You can still Retry if you want to, but if the enemies are too tough, it would be best if you escape from them until you are powerful enough.
Winning battles will always reward you CP (Crystarium Points), Gil (money) and occasionally items. If you finish the battles quickly, the game will reward you bonuses, such as higher chances of getting rare items, whereas winning battles later will reward you little to no bonuses. Sometimes, you can get a recruitable monster upon defeating them.
Paradigm Shift is a feature that is retained from the first game, and it essentially means that it allows you to change your character roles. You can have up to 6 Paradigm sets, with different roles mixed in, with Paradigm Roles such as Commando, Ravager, Sentinel, Saboteur, Synergist, and Medic. For example, the Cerberus Paradigm set is composed of three Commandos, whereas Ravager Paradigm set is composed of three Ravagers. Each Paradigm roles have different abilities, such as Commando specialises in physical attacks, whereas Sentinel specialises in defending against attacks and counterattacking. Experimentation on each Paradigm roles to create best Paradigm sets to be used against all types of enemies is highly recommended.
Winning battles may sometime reward you the crystal of a monster. That means you can use it as your third party member in the game. There are many monsters that can be recruited to your party, and there are some that can't be recruited, such as bosses. Unlike Noel and Serah, each monster have only one Paradigm, which is their own limitation. However, leveling them up enough in Crystarium will make them much stronger, making them a powerhouse in their own Paradigm role. You can also adorn your monsters with various things, such as hats, bags, etc.
The leveling system in the game is similar to Final Fantasy XIII, with some changes. First of all, all of Noel's and Serah's Paradigm roles have their own levels, and each character have only one leveling path. As you increase any of your Paradigm role levels, your Crystarium path will proceed further to a slot, and will gain bonuses such as HP boost, Attack boost, Magic boost, or a new Skill. If you have leveled your Crystarium path enough, your Crystarium path will expand, allowing you to continue increasing other Paradigm roles as well as getting bonuses such new Paradigm roles or Paradigm role bonus. This allows flexibility in leveling your characters' Paradigm roles, as you can even have all of your Paradigm roles to be level 10 at the same time, or focusing on only one Paradigm role. As in the first game, you need to use CP (Cystarium Points) to level up your Paradigm roles, and CP can be gained by fighting battles, or collecting Fragments.
The monsters on the other hand, does not level up using CP. Instead, they use monster materials to upgrade their own Crystarium. Defeating enemies will reward you the necessary monster materials to level up your monsters' Crystarium. As you keep leveling up your monster, the quantity of monster materials needed to increase their level will increase as well. Spending time on farming monster materials is a good investment, since they can be very powerful in battle once they are leveled enough, not to mention they learn some exclusive abilities such as Faith, Bravery, etc.
if you do not have an open mind on how different this game is than previous Final Fantasy games.
If you are fine with it, read this review on.
Story

Both Noel and Serah are journeying to stop the paradox in different timelines, as well as to find Serah's sister, Lightning.
The story took place 3 years after the events of Final Fantasy XIII. After the fall of Cocoon, Cocoon residents have began migrating in Gran Pulse and start living there. As Serah dreamed about her sister, Lightning fighting with a man by the name of Caius, a meteorite strike at her town, New Bodhum. Numerous monsters attacked the town, and an unknown man called Noel saved Serah from the monsters. Noel came from the future, and was tasked by Lightning to bring Serah to her. Serah agreed, and together they journeyed to different timelines to find Lightning, while solving paradoxes in each timeline.
Storywise, this is much better than Final Fantasy XIII's storyline, but it can be confusing as there are many jumps between different timelines. Time travel is a very good concept to be used in a story, but it is very hard to be implemented in the plot to make a good story. Unfortunately, the storyline of this game is around the average, not too bad, not too great. Fortunately, the game does explain some important terms unlike in Final Fantasy XIII, which actually helps you to understand the storyline much better.
Character developments in the game are great, and I especially like Noel's development. His background story is a bit sad and emotional, and the best part is he is from the future. Other characters such as Serah and Caius also have great development in their characterisation in the game. Too bad we don't get to see much of the previous characters in the game, and most of them appear briefly in this game.
Gameplay

Plays like Final Fantasy XIII, with many improvements and some regressions.
This game plays like Final Fantasy XIII, with some differences. First of all, you only have two playable characters in the game. That's right, only two, which is Serah and Noel. Your third party member spot is filled by a tamable monsters, which is gained by fighting them.
Unlike in Final Fantasy XIII, encounters are random, and they are triggered by moving around in areas. When they appear, there is a chance for you to strike them for Preemptive Strike, which allows you to strike them first.
The battle system is the same, with ATB gauge system needed for you to execute actions. You can choose Auto-Battle to have automatic commands being executed immediately, or manually type in your own commands. You can also use items to heal yourself, or change your Paradigm commands by using Paradigm Shift.
Staggering is back in the game. Most enemies have their own Stagger gauge (measured by percentage), and can be filled up by attacking them repeatedly. If you manage to maximise the gauge, the enemy will reach a Staggered state, and will take more damage to your attacks than usual. Be aware that the Stagger gauge will not stay up for long, and eventually will diminish if you let time pass and if you don't attack them quickly. Regular enemies have low Stagger point, whereas tough enemies such as rare monsters and bosses have higher Stagger point.
There is a new feature in the game called Wounding. Some enemies and most bosses have attacks that can cause Wound status, which reduces your maximum HP. For example, if that boss hits Serah with an attack that has Wound status, her maximum HP will be reduced permanently in battle from 600 to 550. Prolonging battles against enemies that has Wound attacks is not recommended, and it would be best if you defeat them quickly.
Unlike in the first game, you can now switch your Party Leader freely, while in the menu or battle. This time, if your leader dies, your other character in the game will become the Party Leader. Subsequently, if both Noel and Serah is dead in battle, you will get Game Over. You can still Retry if you want to, but if the enemies are too tough, it would be best if you escape from them until you are powerful enough.
Winning battles will always reward you CP (Crystarium Points), Gil (money) and occasionally items. If you finish the battles quickly, the game will reward you bonuses, such as higher chances of getting rare items, whereas winning battles later will reward you little to no bonuses. Sometimes, you can get a recruitable monster upon defeating them.

Change your Paradigm set by using Paradigm Shift to turn the tide against your enemies.
Paradigm Shift is a feature that is retained from the first game, and it essentially means that it allows you to change your character roles. You can have up to 6 Paradigm sets, with different roles mixed in, with Paradigm Roles such as Commando, Ravager, Sentinel, Saboteur, Synergist, and Medic. For example, the Cerberus Paradigm set is composed of three Commandos, whereas Ravager Paradigm set is composed of three Ravagers. Each Paradigm roles have different abilities, such as Commando specialises in physical attacks, whereas Sentinel specialises in defending against attacks and counterattacking. Experimentation on each Paradigm roles to create best Paradigm sets to be used against all types of enemies is highly recommended.

Fight monsters to tame/recruit them to your party.
Winning battles may sometime reward you the crystal of a monster. That means you can use it as your third party member in the game. There are many monsters that can be recruited to your party, and there are some that can't be recruited, such as bosses. Unlike Noel and Serah, each monster have only one Paradigm, which is their own limitation. However, leveling them up enough in Crystarium will make them much stronger, making them a powerhouse in their own Paradigm role. You can also adorn your monsters with various things, such as hats, bags, etc.
Each monster have their own unique skill called Feral Link. Feral Link gauge is charged by attacking enemies, healing, etc. Once it is full, you can activate it and use it to defeat your enemies. During the activation, there are some button inputs in order to increase the effectiveness of the Feral Link attacks. How strong it is will be depending on how fast you input the button commands.

Crystarium system is back, with some changes.
The leveling system in the game is similar to Final Fantasy XIII, with some changes. First of all, all of Noel's and Serah's Paradigm roles have their own levels, and each character have only one leveling path. As you increase any of your Paradigm role levels, your Crystarium path will proceed further to a slot, and will gain bonuses such as HP boost, Attack boost, Magic boost, or a new Skill. If you have leveled your Crystarium path enough, your Crystarium path will expand, allowing you to continue increasing other Paradigm roles as well as getting bonuses such new Paradigm roles or Paradigm role bonus. This allows flexibility in leveling your characters' Paradigm roles, as you can even have all of your Paradigm roles to be level 10 at the same time, or focusing on only one Paradigm role. As in the first game, you need to use CP (Cystarium Points) to level up your Paradigm roles, and CP can be gained by fighting battles, or collecting Fragments.
The monsters on the other hand, does not level up using CP. Instead, they use monster materials to upgrade their own Crystarium. Defeating enemies will reward you the necessary monster materials to level up your monsters' Crystarium. As you keep leveling up your monster, the quantity of monster materials needed to increase their level will increase as well. Spending time on farming monster materials is a good investment, since they can be very powerful in battle once they are leveled enough, not to mention they learn some exclusive abilities such as Faith, Bravery, etc.

Non-linear exploration. Travel to different timelines to resolve paradox and to get close to Lightning.
Fortunately, the game's progression and exploration is not as linear as Final Fantasy XIII. As you finish the first Episode in the game, you will be taken into Historia Crux, which is some sort of World Map of Final Fantasy XIII-2. You need to travel to different timelines for different places to solve paradox that has been happening all over.
After defeating certain bosses or progressing further in a timeline, you need to use an Artefact to open a gate that allows you to progress into different timelines. Some Artefacts are gained by defeating bosses, but some Artefacts needed to be found in different areas.
While you progressing in the game, you will come across into a certain minigame called Temporal Rift to solve a paradox in a timeline. There are three categories of Temporal Rift, and they can be easy or difficult to solve. This is a good new feature implemented in the game, as it requires some thinking to complete them.
Like in the previous game, your controlled character can jump, but this time you can manually jump by pressing the X button. This is needed to traverse some platforms, as they are might be far to reach by simply running.

Choosing funny Live Trigger answers can be quite hilarious.
While playing the game, you will encounter a choice based scenario called Live Trigger. Live Trigger is a scenario where you can choose certain answers to progress in the game. Some Live Trigger scenarios doesn't have much impact to the game, but others can bring dire changes to the timeline of the area that you are playing at the moment.
It is to be noted that this game have an auto-save function. Should you quit the game unexpectedly or die in a battle, you can always reload your game without saving your game. You can also save your game manually at the Start button or at Historia Crux menu.
As in Final Fantasy XIII, you can find treasure chests, with two categories. A normal treasure chest, and a special chest. A normal chest contains normal items such as healing items, whereas a special chest contains rare items such as Fragments, weapons, etc. Some of the treasure chests can be hidden, or is unreachable by normal means. If you encounter those problems, you can use Mog to reveal these chests, or throw her to that particular unreachable treasure chest to get it.
Weapons, accessories and items can be bought from a vendor called Chocolina. In most timelines, she will be around to sell items to you. Buying new weapons and accessories is recommended as the battles ahead will be getting more and more difficult. Some weapons and accessories can be bought immediately, but some can only be bought only if you have the necessary materials to buy it.
Fragments are some kind of items that provides new information and details on certain unexplained things happening in the game, such as the disappearance of a certain character, etc. Some of the Fragments are mandatory in order to proceed in the game, and some can be found while exploring in the game.
I love the gameplay improvements in the game. I am pretty satisfied and pleased that Square Enix manage to improve from their previous mistakes in Final Fantasy XIII. Although I can't switch my main party members in the game, the improvements in all other gameplay areas make this game a much better game than the previous game.