I'd like to add my voice to some others out there about Final Fantasy XIII-2. I'm not going to reiterate the game mechanics and content so much as I'll highlight some of the things I liked and didn't like about it.
First off, the story is serviceable for a Final Fantasy video game I don't think it stands out as one of the greats, but it certainly isn't terrible. It's a continuation of the world-ending plot that FFXIII started, but this time it's Serah and Noel's perspective. Aside from a few moments of eye-rolling cheese in the dialogue, by the end I liked both characters, and sympathized most with Noel since that guy has been through some shit in his time. When I arrived at the end of the story, I felt like I had played a relatively long adventure and was ready for the conclusion of this part of the series. I felt like I wanted to play the next one, and I'm still excited for it. Don't expect a lot of answers on specifics like time travel and how characters can fall 50 stories and land with no issues. It's Final Fantasy and shit like that just exists. But I was hoping for a little bit more on what the Fal'Cie are and what all this time manipulation means to them.
Your third party member is a pokemon, or rather an FF monster that you capture. I didn't like this mechanic at first, but really enjoyed it by the end. There's a lot of leveling and "fusing" (like Persona) to make some monsters really shine, and they make all the difference in the world since Serah and Noel do not have every ability at their disposal themselves. I still like the Paradigm battle system, but I'm ready for another different battle system in the next game. The Stagger mechanic in battle is still great. I'm not a big fan of random encounters, but this game does a little hybrid of that, which I'm generally okay with. I prefer the FFXII style of game where you always see the monsters on the field, and they may respawn. But FFXIII-2 is an open game, and in fact you can replay story sequences if you want well after you've leveled up a bunch more. Saves can be made at almost any time (not during cutscenes). I like all the flexibility this game gives us, and I hope they continue that tradition in the next game.
There is plenty of endgame stuff too. I didn't do all of it, but I took on many rare monsters before I stopped playing. I may go back to it at some point since I generally like this kind of thing. There were some monsters, like Don Tonberry, Raspatil, and Yomi that I had trouble beating with my usual paradigm deck at level 99 with everyone. They require specific strategies, which is one of the things I love about FF games. You end up using some of your captured monsters that you never thought you would use in order to defeat some of the more interesting enemies. I thought acquiring and leveling the chocobos to fight with you was fun, and this was the first FF where I thought the chocobo racing was fun. The slot machines on the other hand are not fun, even though they seem well-made. I just don't have the patience for slots. I was good with most of the puzzles too. Most of them were very easy, but the clock puzzles got to be difficult. I really enjoyed those because I got out the pencil and paper for the hard ones and solved them on paper and applied the solution to the game. Very clever.
Of course the presentation is amazing, worthy of a flagship Square-Enix game. I ended up buying some of the music so I could listen to it offline. I generally love the creativity that went into this series, and the art is some of the best in gaming. I like the world that has been created here, and wish there was better dialogue in some parts of the game. It's not awful, but it's not great either. Maybe a better localization would help, although the voice actors are certainly competent. I don't know how a voice actor would be able to lift the cheese from something like "Let's change the future!" without a bit of rewriting.
For a full-priced game you could definitely do worse. Back in the day when I had only $50 to spend on one game, I would generally buy RPGs since you get a lot for your money. Phantasy Star games on the Genesis and FF games on the SNES were some of the best money could buy at the time. I paid $80 for Phantasy Star 2 (plus cluebook!), and it was still a better value than most of the other games at the time. Nowadays, you have multiplayer games that offer a lot of value, and single player RPGs can be all over the place. FFXIII-2 offers a lot of gameplay, I put in about 70 hours myself, and there was still a lot to do in getting all the weapons, accessories and monsters. It's certainly worth a playthrough, even a year and a half after its release, if you're an RPG fan, and it's 18 bucks on Amazon.