Played through Disgaea D2. Pretty fun romp if you enjoy the series in general, though it's unlikely to do anything major to change your mind if you're not a Disgaea fan. I'm bored and feel like rambling so I'll break it down a bit.
The good:
As Disgaea experiences go, DD2 is
incredibly streamlined and convenient. The shop system has been retooled; customer rank, rather than functioning as the maximum shop rank you can achieve by passing bills in the Dark Assembly, simply gives you -3% to purchase prices and +3% to sell prices per rank. (It advances a bit slower than it used to as such, which is fine.) Shop rank is now instead capped by game progress, and advances automatically; the game holds it at a minimum rank equal to your current chapter minus one, and you can pass a Dark Assembly bill to raise it one rank (and only one rank, as it's capped at your current chapter).
Tweaking enemy levels is no longer in the Dark Assembly at all; it's now simply a menu toggle which you can do freely in the new Cheat Shop, which also lets you do things like adjust the balance of how much EXP/HL/Mana you earn. I found that generally, it was best leaving the rates at 100% until you promoted whatever generics you end up using one or two tiers, and then dumping mana gain while boosting EXP and HL as high as the chapter allows them to go; there is vanishingly little need to use the Dark Assembly in maingame in DD2 - at most you'll spend maybe 300 mana per generic you use and then maybe another 300-400 or so split across the story PCs. (You probably will use a couple generics, since for most of the game you only have 5 forced story PCs in this one.)
The master/apprentice system and Extra Gain are back all the way from Disgaea 1, fittingly since this game is a direct sequel. However, this system too is massively streamlined; master/apprentice relationships can be changed at will for free, and there are no funny adjacency requirements on an apprentice using their master's skills/spells (and yes, weapon skills are inherited by apprentices just as spells are). It is utterly trivial to teach your entire team Heal/Espoir for example by apprenticing absolutely everyone to Flonne or a generic healer and having them cast it on themselves in battle 3 times. That's it. That's all you have to do. By the same token, you can create a new generic in deep postgame, apprentice them to Laharl and have the entire sword weapon skill tree learned on the new character in a matter of minutes without grinding weapon mastery levels the old-fashioned way.
Gone, too, are rarity numbers on equipment; it is now simply a trinary system - equips are either normal, rare or legendary, and can be upgraded in rarity by running (a lot of) Item World. Common items upgrade to rare when you clear 30 floors in them, and rare items upgrade to legendary when you clear 60 floors in them. Unlike in previous Disgaeas, if you clear an item's world in its entirety, you can now rerun it for even more item levels (if you're so inclined for aftergame, you can actually level items up to level 999).
As this is a direct sequel, the core cast from the original Disgaea (Laharl/Etna/Flonne) is back, and you have all three of them for the entire game. The Disgaea 1 cast is probably my least favorite Disgaea cast, but this game handles them, IMO, better than the original game did - possibly because it doesn't have to waste time developing them and can just jump right into the crazy hijinks. Sadly, none of the other Disgaea 1 characters return as playables besides those three, and only one of them even appears at all. DD2 is pretty light on story PCs in general: you get one at the end of chapter 2, another at the end of chapter 4, and then you don't get the last forced story PC until just before the final chapter (10). There are, however, two optional story PCs that can be recruited in maingame (after chapters 5 and 6 respectively); both are worth it IMO.
Unlocking new tiers of generic classes is back to the (superior) Disgaea 1 system: based solely on category and level. You can level a tier 1 up and unlock all tiers from it - no need to level up, reincarnate to tier 2, level up again, etc., etc. Even if it wasn't back to that standard, you wouldn't need to anyway - as briefly alluded above, generics can now promote to their class' next tier now without reincarnating for (current tier*100) mana or thereabouts.
The bad:
As Disgaea plots go, this is one of the weaker ones really. There wasn't a whole lot left to *do* with this cast after Disgaea 1, and it kind of shows. It doesn't really detract from the game too badly, but coming off of Disgaea 4's strong effort it contrasts quite a bit.
Also, as mentioned, weapon mastery is back. At least you only have to really grind each weapon once and then you can just apprentice all the skills around after that.
General commentary/things that aren't good or bad:
Overall, in a lot of ways DD2 played like a heavily modernized, streamlined remake of Disgaea 1. This is not exactly a bad thing, as it does keep most of the good things from later Disgaea games while adding some of its own (CHEAT SHOP HYPE), but weapon mastery returning is arguably a regression. Magichange is gone, as well, replaced by monster mounting; this is a fairly lateral change IMO - humanoid PCs can "mount" monster PCs; while mounted, the combined unit cannot use either any of the monster's skills nor the humanoid's weapon skills; only basic physicals and any magic the humanoid PC has learned are available, plus a "Collaboration Attack" which is basically functionally the same as D3/D4 magichange specials. Unlike magichange, mounting has no time limit. The combined unit uses the defensive stats of the monster, and the offensive stats of the humanoid, as far as I can tell; if the monster is killed, the humanoid is left on the field still. Overall I found monster PCs still pretty good.
I'm not the right person to stat topic the game since I grind a little too much, but I think it'd be fun to speculate on how these PCs would look in the DL in a Futurama or the like, so I'm going to do that below. The new characters will be tinyfonted for spoilers but not the main three. (Note: All "stat boost" evilities cap at +200%.)
Laharl:
He's pretty much the same as his D1 version. In-game, he has two different evilities: one that he carries for chapter 4 only, and one that he has for the rest of the game outside of chapter 4. In aftergame you can switch between his evilities in the Dark Assembly; switching to his chapter 4 evility is trivial but switching back to his regular one is expensive on mana and has a low pass rate. His standard evility gives him +10% to all stats for every unit KOed in the battle (until the end of the map, and both sides count), while his chapter 4 evility adds the restriction that the KOed units must be equal or higher level to him, but ratchets the stat boost up to a whopping 25%. Sadly neither of these evilities do a damn thing for him in the DL. He comes with swords by default, and has A affinity with fists/swords/axes. He is likely better off with fists than swords in this game, as his innate skills give him all the AoE he really needs and fist damage is generally better on single targets. I ran him with swords and found them surprisingly a little underwhelming compared to my fist-using generic or even Etna's spears.
Etna:
Solid upgrade from the D1 version, I think, no matter what. Spears are better, spear techs are better, and she's just all around better. Starts with spears, has A in spear/gun/axe. She probably wants to stay with spear. She has a spurious claim to a very overpowered spear for "plot" reasons as well, though it's totally missable and it's not actually unique to her so I could totally see not allowing it. (Specifics: You have to pass a bill at the Dark Assembly to make her stop following you in the base - which costs 10 mana and always succeeds - then hit the two hidden switches in the Overlord's Castle to open up the secret room where her diary was in Disgaea 1. The switches are in the exact same places as D1, too. Then you have to read the entire diary and you get the weapon. The weapon is a "unique" in the sense that it's not in the standard rank scheme for Disgaea equipment, and the description in-game specifically calls it "Etna's favorite spear"; it's guaranteed legendary and has 1500 ATK/300 DEF/262 RES/262 HIT plus whatever its innocents grant. However, you CAN equip it on any spear user. It's only there in the aftergame, though you can do it immediately upon clearing with no other requirements.)
Like Laharl, Etna has two evilities: one that she carries for the entirety of the main game, and a second which she gains (in addition to her original one, not replacing it) immediately on game clear (automatically; nothing special must be done to unlock it). The maingame evility boosts her damage by 50% against full-HP targets, while the aftergame evility doubles(!) all her stats if she's the only non-Prinny PC on the map (being alone counts!) Obviously if you allow her this, she's pretty terrifying in duels.
Flonne:
Definitely upgraded from the D1 version as well, even if you don't allow her spells learned from Extra Gain. Staff physicals now are based on INT and are ranged. Add to this that Flonne can counter, and that DD2 counters are now universal rather than only triggered by basic physicals - specials and spells trigger counters just as physicals do - and the fact that Flonne's attacking specials aren't too bad anyway. She gets S mastery in staves and A with bows and books; going books gives her a sleep weapon skill at the cost of ranged counters. Like the other two mains, she has two evilities: one which she carries for chapters 1-8, and a second she carries for the final 2 chapters. In aftergame, she returns to the first evility and you have to spend (a lot of) mana to get the second evility back. The second evility is the one she uses against the final boss though. Her initial evility gives her +10% to all stats whenever she heals someone to full HP (until the end of the map); her lategame evility gives her percentage stat boosts when she is healed, equal to the percentage of HP she regained (so if she's healed for 50% of her HP - overhealing doesn't count - +50% to all stats).
Oh, and she innately learns healing spells. Yeah, her second evility is absolutely insane for dueling anyone who doesn't OHKO her or status her to death. It's about as broken in-game too.
Sicily:
Eeeh... well, she's a slightly better D1 Flonne, I guess. She's got S in books and A in staves; books are really not great weapons, but since she doesn't get innate magic of any sort she depends on their weapon skills for much of her offensive game. So it goes. Her specials are basically "Laharl but INT-based", and her stats are much the same really. Her evility reduces all elemental damage by 75%; this is processed separately from the standard elemental resist system (and stacks multiplicatively with it as such, not additively). It doesn't catch Star element; personally I'd interp it as catching all common elements, but not stuff like the esoteric SO elements or Almighty or the like. Book weaponskills give her a sleep skill, which helps some.
Lanzarote:
She's a palette swapped Archer that trades some offensive stats for stat-buff spells, including some which are normally unique to the Sea Angel monster class (and which cannot be apprenticed onto other PCs). DD2 stat buffs are +50% stat for 3 turns, so this is good, but she can't buff DEF or RES. Her evility is simply +4% all stats to all allies and -4% all stats to all enemies, nothing too interesting. Most of the unique buffs are irrelevant in the DL (one gives +50% crit rate, which is nice). Standard weapon is bow (S), and she has no better than B in any other weapon.
Barbara:
Basically a palette swapped Heavy Knight with a different hair style. Standard weapon is spear. She only has two specials but they're pretty good. She has A in sword, spear and axe, and probably just wants to stay with spear since she's a late PC and she starts with the most levels there. Her evility boosts her attack and defense by 50% and makes her always counterattack (if in range) when she is defending... which means she probably just wants to spam Defend in duels and let things kill themselves on her as that's likely to be her best damage if her opponent can't outrange her.
Asagi:
She's a maingame PC this time, if an optional one! She's got S in guns, nothing above B elsewhere, and has the same skillset as her Disgaea 4 "HD Asagi" DLC incarnation as far as I can tell. Her evility is useless in the DL (whenever she performs a Team Attack, she attacks again, up to a maximum of 3 times if she repeatedly Team Attacks). Gun skills are decent and she can possibly outright kite with them since she has 5 movement as well. Hmm.
Porkmeister:
The other maingame optional PC and the only story monster. Like his father Hoggmeiser in Disgaea 1, he's simply "generic Minotaur with better stats and better specials" and a unique evility (in this case, +30% all stats whenever any "Overlord" is on the map, so nothing in the DL). Eh.
Final boss:
Well, all he does is spam one massively overpowered attack (it OHKOed all but one of my PCs it hit), but his evility makes him a potentially very interesting dueler. His evility drains stats from nearby units (regardless of allegiance) and adds them to his own: 30% of base (unequipped) stats at point-blank range, -3% per square of distance between him and the unit.EDIT: A few added notes that might be helpful for anyone who DOES stat topic DD2 sometime:
- Final boss is level 80. I'd probably take endgame levels somewhere right around there, though getting there would take some grinding, in large part because the final boss' design strongly encourages overpowering him with a single PC supported by a very tanky healer. In my case, with moderate grinding, I had levels in the high 80s/low 90s and most of my characters were getting OHKOed by him.
- DD2 counters are the most inclusive things I've ever seen, in sharp contrast to counters in early Disgaea games: everything offensive triggers them, whether basic physical or special physical or magic, and whether ST or MT.
Also, I added another point to the good things above.