As addictive and fun as it is bright and colourful. With a solid story and great mechanics, it delivers on every level.
Let's start out with the graphics. In one word: Beautiful. Everything is bright and cartoon-y and done in the cell shading style that was oh-so popular a couple of years ago, yet it manages to break out of that mould and become something all of its own. The world is huge as well, full of little nooks and crannies and visual differences in the different regions and towns you will traverse. Hours can be spent (enjoyably, I might add) simply exploring the vastness of the "main map".
That's a good point to transition into the next best feature of this game, its vastness. The story in Dragon Quest VIII is nearly as long and engrossing as that of Final Fantasy XII, although it does lack the serious tone and urgency present in that title. This is a much more 'fun' adventure, a tone that perfectly matches the aforementioned visual feast. It also has many side quests and mini games that could easily push it past the 100 hour mark.
Sound is also impressive in this game, especially in the music department. Deep, varied and engrossing scores complement the ongoing story and action perfectly. FX are hard hitting when they need to be and not overly cartoon-y, which in retrospect is a good choice. The voice acting also deserves special mention. The script is excellent and the voices themselves are perfect for each of the characters; I would say it is second only to Final Fantasy XII. No wincing is to be had in this story.
Dragon Quest VIII also sports a good combat/levelling system. It's the same story as with most traditional RPG's; choosing whether to slice a foe with your sword or cook them with a well placed fireball. But a little bit is added through skill points in the levelling system. You need to choose where to add an alloted number of points each time you level (the choices being each characters chosen weapon proficiencies or their individual traits). While it's a nice touch, it would be more fun if more levelling was involved.
Which brings us to one of my two main complaints about the game. It takes A LOT for you to level up. And quite often you will have to spend time levelling up before entering a particularly difficult area. Things got much easier once I was able to revive a fallen comrade, but that was about 20 hours into the game.
My other main complaint is more of a pet peeve and lies with the main character himself. I have a strong dislike for the silent main characters. They react to the world around them and yet offer no voice to the happenings around them. Chrono Trigger was the first game I came across where this was happening and it would have been much improved had the developers not done that. To me, this is laziness on behalf of the designers. Knights of the Old Republic went this route, but they chose to let the player decide how the character could react, which worked very well. It can go the other way, however (Tidus in Final Fantasy X was a whiny, limp-dicked douche), but if you have a strong story team (which Dragon Quest VIII does), the chances of that are quite slim.
However, Dragon Quest VIII is a masterpiece and a must own for every RPG enthusiast.