Excellent Story, Excellent Game play, However as always NIS leaves it broken.
I've beaten most of what there is in this game, minus a few tings.
1. I still haven't beaten Baal, even once.
2. Haven't finished all the Dark World
3. No Land of Carnage yet.
BEGIN
Story: The story line is a fairly good story by RPG standards. It's got a few cliche' moments but that is to be expected about anything. I'll skip over the story in general because you either know it, or it would be spoilers for you. But I must say the story is the best Disgaea to date. That's my honest opinion. And even though I thought the first one's story would never be dethroned, it has been. It's long and hearty in the story despite being a couple episodes shorter than Disgaea 1 or Disgaea 2, it FEELS longer.
Characters: The moment I ran into those Latino Boars the Vato Bros. I knew I was in for a treat as far as the cast. You can expect the same insanity you've become use to. I cannot really point out a character in this game that actually got on my nerves. I thought for sure Master Big Star was going to irritate me but he's actually quite tolerable. The cast is strong and dynamic, it was very good but not quite as good as the cast of Makai Kingdom.
Music: The sound track is done reasonably well. There are many tracks I like. However... There are some in this game that make me want to pry my eardrums out with a screwdriver. When you hear the Tutorial music you'll know what I mean. However the theme that happens when you fight the Overlord or the Super Hero/Baal is very good! However because of the more irritating tracks it's getting a lower score.
Voice Acting (English): Top freakin notch. Even the in battle voices are a vast improvement over Disgaea 2. Personally though I think Beast Masters & Cheerleaders should have their voices swapped. Some of the things they say in battle are really... well odd. Like Marona for example is always talking about noodles and such. I think she's hungry. No voices are really horrible. But the one I think could use some improvement on is Salvatore in the story. But since she's not really a main character I'll let it pass.
Game Play: The game play is classic Disgaea style with tweaks all over the place very fun to play but does grind on the patients after awhile. But thats to be expected with anything that has grind in it.
Innovations
The class world system: It allows you to buff up your character's aptitudes it's like nothing they've ever previously included and it's extremely handy in that sense. However the downside to it is you HAVE to use it to learn a lot of skills. This can make gaining your basic weapon skills much more difficult than in the past titles. Quite irritating at first because of the mana costs of everything. One thing that is definitely annoying is that the ultimate skill trainer is on the last level of the dungeon (After clearing all the geoblocks) And most of the time he doesn't show, so you could be looking at a long period of time before you get all the skills you want.
Geo Blocks: They add a 3D aspect to the puzzles in the game that Geo-panels couldn't. They dissolve when they touch one of the same color, which can sometimes make a puzzle easier. However at the same time it can also make things more difficult as there is much more clean up to do. In the item world the puzzles are pretty much simplified. Now you are able to stack all the different colors up on top of each other and the clear on the color of the bottom cube. Whack the bottom cube out and they all explode completing the puzzle.
Special Move Combination: Love this one, when moves combine not only do they gain more power but this also moves the flow of battle along quicker.
Level Spheres: Oh god yes... the best addition to the game it takes a lot of the stress out of getting your gear leveled.
Reverse Pirating: It is sometimes difficult to get anything done in reverse pirating, especially in the higher stages. The levels are rather large and sometimes certain things you may want are difficult to access however if done right this can be an invaluable feature to your experience, hauling in tons of items, specialists, and level spheres you otherwise would not have had.
Multi-Pirate attacks: This can be a mess if you get jumped by a lot of pirates that are stronger than you, but it cleans up the nightmare many players had about pirate hunting in Disgaea 2 because multiple groups of pirates can attack you at one time.
Skill boosting; This is a give and lose type of thing. No longer does leveling up your skills add new dimensions to it like extra attack zones instead you must boost it with Mana. This boost increases the effectiveness of the skills allowing it to do more damage or have a better success rate. However if you pump it too much you can find yourself having a crippling SP cost to use the skill this is very bad for long fights. So it's good to mix it up, having some uber pumped skills, and others not so pumped. Lower level characters it is harder on. But for example you can have a single attack costing over 3000 SP. And once you upgrade thats it you can't downgrade it again. It should also be taken into consideration enemies who have buffed skills have deceptive power.
Post Game: Unlike in the others post game is actually divided into it's own little story, I think this makes it more enjoyable as it has it's own arch and everything.
Dark World: Dark world has completely changed as we know it, now it's just a series of mind bending puzzles. However they aren't too difficult for someone with their head screwed on right. GONE is the Dark Sun, however some of his most annoying effects are present in the form of Geo cubes.
Manual Tower Attacks: Unlike Disgaea 2 you can actually choose the tower attack you want. Simple eh?
As you can see there are a lot of innovative things they are trying to do with this game. Most innovative of all is the Downloadable content coming soon. I say they added more features to this one than they did Disgaea 2 vs 1.
Brokenness:
As always NIS somehow seems to overlook some things. There are some points where the game actually slows down. It's been claimed that it slowed down in larger item world stages but I have yet to see that happen. The only time I've seen any slow down was while I was inside the classroom. The full 64 character class room mind you, but it's very noticeable.
And the most important part of this broken state. It's called a Puppy Paw Stick. It's innocent enough from the looks of it, 20% chance to steal an item upon death of the enemy. However theres a serious flaw that must be underlined.
Within the class world there are enemies known as dropouts that are identical copies of the character whom you are within. They possess all their equipment as well. A thief has a 0% chance to steal from these clones and NIS even removed the fact you can be cloned because of the puppy paw stick. (At least I think so.) However they overlooked the drop outs getting stolen from with the puppy paw stick. This allows you to steal items you've already leveled and duplicates their specialists as well, which allows you to very easily multiply the specialist level until you reach it's maximum. While it's a relief for people with large armies it's unarguably broken allowing you to amass so much power in a short period of time that it utterly butchers the replay value. Who wants to do a 100 level item world for a new powered up item when you can simply do 10 levels of class world and potentially get it in minutes?