Persona 3 makes me think about cycles.
Back when the console RPG was just starting out, with games like Dragon Warrior, Final Fantasy, and the NES port of Wizardry, the games were mostly grindfests. You walked in circles around Corneria for three hours collecting money and experience so you could survive the walk to the next town over, where you would need to spend another three hours running in circles before you could move on.
Games eventually evolved to a point where the grind wasn't strictly necessary, which happened right around the time where CRPGs became a lot more story-oriented. There were more CRPGs, they had more of a plot arc than they did before, and grinding was almost never required to progress. Some of them were, in fact, designed in such a way that grinding would wreck the game's power curve; for example, Yang leaves the party and never returns to it in Final Fantasy II because at high levels, he's the most dangerous character in the game.
The grindless CRPG continued until relatively recently, when Final Fantasy XII, Rogue Galaxy, and now Persona 3 have brought it back in full force. Persona 3 requires a lot of grinding to succeed; it's almost a roguelike, really. You spend a lot of time exploring the randomly changing hallways of a dungeon hundreds of stories tall, farming it for drops off of monsters and fistfuls of yen so you can buy better gear off a slumming police officer in a mall downtown.
At the same time, it's... well, it's not entirely a dating sim. It's a high school simulator. You spend your days studying or joining clubs or wooing the girls that live in your dorm, and your nights sticking sharp things into evil things' heads.
I'm getting very far ahead of myself.
Peraona 3 begins on April 9th, 2009, as your character arrives for his first day at school. That same night, you discover there's a twenty-fifth hour of the day, between 12:00 AM and 12:01 AM, called the Dark Hour. During this time, monsters prowl the streets, and most people fall asleep.
You're not one of them, and neither are the people in your dorm. You all have access to Personas, weird fragments of your personality that take on the form and powers of figures of myth, and those Personas also prevent you from falling asleep during the Dark Hour.
As members of the Specialized Extracirricular Execution Squad (SEES), it's your job to find out why there's a Dark Hour and where the monsters are coming from. During the Dark Hour, your school turns into an enormous tower called Tartarus. Operating on the theory that this might be some kind of clue, you and your team will investigate Tartarus looking for answers. Somewhere near the top, you may find them.
Thus, by night, you get to run through a dungeon killing monsters. By day, though, you're an ordinary high school student. Most CRPGs might gloss over the daytime stuff, but Persona 3 makes it almost as important as the dungeon delving.
Your character has the unique ability to command more than one Persona, each of which belongs to a certain Arcana. Everyone you meet belongs to one of these Arcana. Thus, if you start, strengthen, and maintain relationships with people from each Arcana, the Personas you use will be strengthened in turn. Being a decent friend makes you a better adventurer, and so on.
Further complicating this is the fact that Persona 3 operates on a fixed time limit. Each day you spend in-game is a day you can't get back, and the game will progress without you if it has to. You are constantly forced to juggle your social links, your dungeon crawling, your monetary supply, and more, and all of this within sort of a time limit. You're never sure if you'll have time to do everything you want to do, sort of like in real life.
Persona 3 juggles all of this fairly well, and once you get into it, it's hard to stop playing. Even if you never thought you'd play a datesim, it'll make you care whether or not that one girl likes you.
My biggest complaint about the game is, basically, the grind. When you enter the dungeon, you're either there for fetch quests or to get from point A to point B before your party members are too tired or sick to continue. There's very little story there, and the bosses that show up mostly show up because they're standing in your way. Persona 3 has a lot of very well-told story in it, but surprisingly little of it's in the dungeon itself. You basically take a time out from a datesim every so often to play what feels like an old RPG.
Persona 3 is, despite that complaint, one of the best RPGs on the PS2, and in fact, on any console. It has characters you'll care about, a combat system that's easy to get into but hard to master, enough of a difficulty curve that you'll feel like you're working for your victories, and a truly bizarre and memorable soundtrack. It's very, very grindy, though, and I have a hard time getting into that.