I can not comment on the multiplayer aspect of the game, as I am yet to experience it. Therefore I will be reviewing this game purely on its single player merit.
The game is very classic in its delivery, and anyone who has played a JRPG will be familiar with the concepts. These games resolve around a familiar journey of visiting new towns, solving their problems, gaining a reward for this and then moving onto the next area. Each town has a shops with slightly more powerful items, rewarding the player for grinding the gold, and the desire to optimise your party at each stops ensures the grind is not without reward.
The twist is for the most part random encounters are not part of the game, with your foes being represented by a sprite on the map. Therefore you can, to a point, grind as much as you wish to. This is also useful as you complete your monster index, a bit like a pokedex in pokemon, where you seek to kill one of everything in the game. The crafting aspect of the game also rewards the player for killing monsters, the items dropped can be used to craft powerful weapons.
I found the story to be the classic JRPG formula with a twist and the delivery through some strong characterisation and use of language to give each town a distinct feel, culture and ensure each zone is a different experience to the next. The game does suffer however by allowing you too much customisation, your party members are player created, and therefore nothing more than your personal battle slaves with about as much personality as a paper cup. I missed having conflict in the party through each member having their own story, something that is a strong theme in other JRPG's I have played. I did enjoy bringing Cloud, Tina and Aeries along for the ride, the creation tool allowing you to create a pretty accurate representation of whoever you wish.
Sidequests are spread across the globe, from simple fetch x, or kill x, to longer plotlines that unlock new job roles for the player to try out. These are an interesting way to reward the player for new content, and being able to dip into them as and when you wish to is a good way to extend the game, and further reward the player for killing monsters and leveling up.
Furthermore the game provides a deep and complex crafting system, which has pages and pages of items to craft and use to improve your party. This is supplemented by the class system, where the player can switch job roles, with 6 available initially and unlockables providing even more customisation. These additions ensure there is a lot of replayablitiy of the game, and ensures it has enough challenges to keep the player coming back.
The graphics are impressive, bright and vibrant and the sound ensures the classic JRPG atmosphere is maintained, through upbeat battle music and memorable melodies in each town or city. The game lacks a little in the sound effect department but this doesn't detract from the final product.
Overall Dragon Quest IX is a classic JRPG with a couple of tweaks, which deliver a satisfying and rewarding game experience. Despite it suffering from having too much customisation it still delivers exactly what you'd expect, and for that I have to recommend it to all fans of this genre.