Not sure if serious
Back in the late 1990s, it was trendy in JRPGs to ape Evangelion's nihilistic nonsensical mishmash of surface-level psychology and religious concepts with pretentious vacuous post-modernism. This made quite a few of them shit. Somehow, this jumble of bullshit really appeals to a lot of your standard Japanophile shut-in "troubled teenage years" sort of market, who swear up and down its THE GREATEST THING EVER WRITTEN OMG. See also Xenogears for reference.
Innocent Sin is more of this general category of shit. It's not nearly as depressing, but I think it may actually be the worst of the bunch on the whole, because it creeps in so slowly and is so insidious. The first 75% or so of the game isn't like that at all. It's actually a fairly interesting story that explores the idea of what would happen if rumors could become reality if enough people started spreading them. It has sympathetic and well-developed characters, great art and music, and an interesting and unique atmosphere. Then it dumps all the retarted bullshit on you at the tail end, after you've already sunk 40+ hours into it.
Not only that, but the first 75% of the game or so doesn't really require any grinding at all. You can just play it normally with little need to stop in areas and run in stupid circles until you have enough EXP and money to take on the next Foozle in your path. But all that changes, again, right near the tail end, after you've already sunk a hefty amount of time in and feel like it would be a shame to give up this late.
Let's go back to the beginning and work up from there. The game takes place in the universe of the first Persona game, but ten years later, and in a different city. The adult versions of some of the previous game's characters bop in for cameos frequently, but the main story revolves around newcomer Tatsuya, a stereotypical "cool" Japanese schoolkid with studied Iori Yagami slouch. The first half-hour of the game is actually some of the worst of it as there's no fighting or action whatsoever and everyone fawns all over Tatsuya so hard it seems like the game is just going to be a total Japanese nerd power fantasy wankfest, but the tone abruptly shifts when Tatsuya and his crew play the "Joker game", the new hotness that is going around as a rumor. It's said that if you call your own cell phone number, a character named Master Joker appears and grants you a wish. Except Tatsuya and crew soon find out that sometimes he arbitrarily turns people into Shadow Selves, a ghost that is soon forgotten by everyone that knew them, or just melts their face for no apparent reason. After turning some stooges into Shadow Selves in front of him, Master Joker tells Tatsuya and his friends that they're going to die for some crime they committed in the past, but no one can remember what this fuckwit is going on about, so Master Joker decides to leave them alive until they remember, but constantly hound them with demons just for the lulz. Fortunately your little crew can also use Personas, which are pretty much analogous to the Espers of Final Fantasy VI - a magical being that you equip which grants you a suite of spells.
You practically need a linguistics degree to figure out what spells do in this game
The gameplay is light years ahead of Persona, at the very least. Everything is similar, but tweaked to be much more player-friendly. The game isn't in clunky 3D anymore, and you don't have to manually truck around some huge city map where you can get attacked at any time anymore. It doesn't have the constant painful load times of the original game, and battles move at a much zippier pace, and also drop the "movement" aspect that was so annyoing.
The localization is a moot point since it was never brought to the U.S. (more on that later.) You can play it in English, however, thanks to the noble efforts of a fan translation group, who did a really good job. So you don't have to deal with the story being butchered and huge chunks of the game being excised if you want to play it in English as you did with the previous game.
While we're on the subject of positives, the soundtrack deserves special mention. It's really good, and a lot of care was put into it - every location has its own unique song, even the cloned drugstores that pop up all over the place each have their own special rendition of their theme song!
Like I said before, the first 75% of the game or so is interesting, moves along at a good pace, and doesn't demand much grinding of you. Gradually, though, things start to fall apart. The first issue is that, when the difficulty DOES step up and force you to grind, there's actually 3 separate tiers of grinding you have to put up with. There's normal EXP grinding to raise character levels. But each of the equippable Personas has to also be used repeatedly in battle to level them up, and unlock all of their spells. You also can't get the most advanced Personas until you level a shit ton of weaker ones to their maximum level, then take them back to trade them in for the newer model or something. Then there's the "Contact" system that is reprised from the first game. Instead of fighting demons, you can attempt to chat with them. Each character has a different range of approaches, and demons respond in different ways to them. You have to figure out what demons want to hear, and if you tickle their fancy enough, they make a Contract with you and give you Tarot Cards, which are needed to summon better Personas. The Contact system is way better than that of the first game simply in that it's easier to understand what the fuck is going on thanks to the much better translation, but there's still problems. One is that the demon responses often just seem to be completely random, and if you make them mad three times during a contact, they refuse to listen any more for that battle, and get a free set of turns to attack you with. Often figuring out what the hell they want is just a frustrating and time-consuming matter of trial and error, but then once you do know what they like, the same pattern works every time. So then it turns into a mindless card grind.
I was prepared to call the first 75% of the game a very good experience, but with a bit too many Grindan Adventure elements and iffy design decisions to reach excellence (during that period there's a few dungeons that are not only timed, but don't allow you to save, and also ambush you with a really tough boss at the tail end, so if you're unprepared for them and lose you have to do a 30 to 40 minute stretch all over again.) Then, in the final quarter, the game just went all to shit. For those of you out there who've already played the game and are reading this just to get into a good and frothy ButtRage over how I don't share your opinion or tastes, I'm referring to the period from starting Mt. Katatsumuri to the end of the game. First, the dungeons start to be populated with cheapass bullshit enemies that use cheapass bullshit spells, the only real solution to which is Grindan until you can consistently overwhelm them. The encounter rate also jumps up to literally a battle every five steps or so. And while the dungeons are an improvement over Persona, it's still basically long stretches of bland, repeating textures, and most of them in this period stretch on for waaaaaaaaaaaaaaaaaaaaaaay the fuck too long. And the new Persona spells all have bizarre names that are not at all indicative of what they do, requiring you to read a FAQ to see what you're getting or just Grindan Forever to get enough cards to summon most of them, then Grindan them all up to make their spells available.
Smirky Hitler dropped a few pounds and now speaks Japanese for some reason
All this is still tolerable up until the final dungeon, as the story remains fairly interesting, even if totally bereft of reason at times. The characters are good, and you want to see what happens to them, and get their full backstory. So there's at least some reason to go through the tedious bullshit. But then you hit the final dungeon, which has to be one of the worst pieces of final dungeon design I've ever seen in gaming. It shares the problems of other dungeons - way the fuck too long, traps you inside for a really long time without any warning you'll be stuck in there that long, uninspiring bland textures repeated ad nauseum, bullshit enemy groups. But it also adds nearly unavoidable garbagey-ass traps all over the floor everywhere, and an absolutely ludicrous encounter rate. OK, but still, EVENTUALLY you're allowed to teleport out and get a shortcut from town to near the end, and you can always talk your way out of battles and such. So still not a deal-breaker.
The game held on to the Good Face rating until the final bosses, basically. Aside from a couple of cheap fucks that require grinding to beat, most of the game's bosses to this point actually were on the easy side. The only challenging ones were challenging because they had some bullshit spell that hits everyone in the party for huge damage while also freezing two or three people for a few turns, which there's no way to block or evade for the most part. But they still weren't that bad because they didn't use that spell every turn, and their other attacks didn't dish out enough damage to outpace your healing. Well, that all changes with the final two (back-to-back) bosses of the game. They have the bullshit spell that hits everyone for big damage and either freezes or confuses 2 or 3 for a few turns. But they ALSO have the fine bonus of knocking a couple of people dead here and there for no explicable reason. And they have just ludicrous lifebars. Up to the second-to-last guy, the most health a boss has in the game is 5000 HP. The second-to-last guy has 7500, which wouldn't be bad if it was an isolated battle. But then you get chucked into a fight with a guy who has fucking five parts, and the main one that you need to kill has 15000 HP!!! Fighting these two guys is this ridiculously drawn-out battle of attrition, as two characters get killed instantly, then two others have to burn their turns either reviving them or healing the group, so one guy per turn plinks away for maybe 300 or 400 damage or so at best. It's just a fucking bullshit masochistic waste of time. Neither one is even impressive looking, they look just like the same boring-ass plain old bosses of the rest of the game, complete with uninspiring backgrounds. Kefka, Giygas, these are final bosses etched into your memory forever by the badassness of their form and setting. These guys you'll probably forget within a few months because they're so fucking boring.
That's one half of what dropped the game to a Meh. The other is the ending. Lemme go ahead and say there's gonna be some SPOILERS in this paragraph. Generally I try to avoid these, but this fucking game just offended me so much by wasting so much of my time that I just feel the need to warn anyone who isn't already inducted in the Cult of Persona-lity not to also let this suck out days of your life. First of all, "Persona 2" was actually divided into two chapters - this game, and a follow-up called Eternal Punishment. If you're interested in playing these at all, you might as well just skip straight to Eternal Punishment, because this game ends up really just being little more than a long advertisement for it. You grind all the way to the end of Innocent Sin, and find out the whole thing was basically a bet between two deities - shades of Piers Anthony's Xanth - about whether humanity can "rise above their contradictory nature" or not. Just as you think you've won, some minor character runs in in deus-ex-machina style and does something that lets the bad guy win on a technicality. So the fucking Earth gets destroyed. Seriously. But don't worry! Good Deity will "reset" everything for you to give you a second chance - in Eternal Punishment! That's right, the whole events of this entire fucking game basically didn't happen and don't matter, and it's all a giant dicktease for the "real" story in the second half.
Seriously. Atlus. Go. Fuck. Yourself.
The one mildly redeeming bit of all this is that you get the option to punch the Good Deity in the face at the very end for being such a fuck. But that hardly makes up for 40 to 60 hours of life down the fucking tubes in some pointless po-mo jerkoff exercise.
This game is finally about to be localized on the PSP in the West for the first (official) time ever. The given reason why it didn't get localized on the PS1 (but Eternal Punishment did) was because Hitler is a minor antagonist (he's the second-to-last boss, but seriously he only has like three brief appearances, and really hardly matters to the story at all), there's Nazi imagery all over the place, and a couple of things that are suggestive of gay sexuality. Apparently a lot of that is being scrubbed for the PSP localization. But, in order to keep from completely hating Fatlus for what just happened here, I like to think that the real reason is that whoever makes Western localization decisions played both games back in the day, said "WTF there's no point to this first game, it's just a bunch of time-wasting dicktouching", and decided to just do everyone a favor and only port the game that was actually relevant and worth playing all the way through (Eternal Punishment apparently recaps all the major scenes of this game with flashbacks as you go). That's probably not what actually happened, but let me believe it. It's the ony comfort I have at this point.
Now, to be fair, maybe Eternal Punishment ties up everything that happened here into a satisfying conclusion. The fundamental issue is releasing them as two separate, full-priced games. I'm trying to picture myself paying $40 or $50 for the upcoming PSP release, putting in all the time I just put in, then getting "LOL! THIS IS NOT A TRUE ENDING!" after being cockslapped by two ridiculous bosses and a series of really tedious dungeons that require a shit ton of grinding. I mean, all the game really ends up having going for it is the setting, story and characters. The battle system is outdated, a little too slow and clunky, and incredibly repetitive with how much the game expects you to fight. The Persona system is needlessly confusing and trial-and-error. The final dungeon design is lame and boring, I mean you're not even sure it IS the final dungeon when you're in it, and then the final bosses both have a boring design and just have the same lame pattern that all the other game bosses have, just with their stats and bullshit spell effects jacked up more. To tell you "HERE'S A STUPID MESS OF AN ENDING, NOW LOL 50 MORE DOLLARS AND 50 MORE HOURS OF GRINDAN TO SEE THE REAL STORY OLOLOLOLOLO" at the end of all that is just utter bullshit. These two games really should have just been fused into one concept. Having to suddenly start over at level 1 in the middle of the game would have been significantly less irritating than having to buy an entirely new game (no doubt packed with recycled assets) AND start over, but they could have just written it in such a way to avoid even that pitfall. Nerds of the Interwebs, please stop enabling this behavior. Stop telling game designers they are "BRILLIANT!!!111!!!" when they pull bullshit stunts like this. I'm gonna leave it at that, this game has wasted enough of my time already.
* Gameplay Video