Fun, for a while.
Unfortunately, it suffers the same fate as most free-to-play MMOs, in that the quest system is lacking. There is an abundance of quests at the onset to keep you leveling just from quests until around the early 20s, then they start to die out. They have implemented daily quests as somewhat of a solution to this problem, but those quickly become repetitive and boring and most players are relegated to running the missions maps over and over (and over) for EXP.
The art style is almost what I would classify as chibi-style anime, which is slightly too cutesy for my tastes. However, it is done quite well (for the most part), from the player characters, to the monsters and the backdrops.
There are a decent amount of choices as far as character customization and armor styles (compared to other ftp MMOs). You start off as 1 of your stardard 4 basic MMO classes (Warrior, Mage, Archer, Thief), then can choose between two specialized classes at level 20 (after completing some quest prerequisites), then another specialization at level 40, and so on. There is a fair amount of skills to choose from to prevent every single player class from being a carbon-copy of the next.
Another turnoff for me was the lack of support for higher resolutions. I believe the highest available res for this game is 1280x1024 (no widescreen support). That's really just unacceptable for an MMO in this day and age.
If you do choose to try this out, I would highly recommend using a gamepad to play as it lends itself well to this style of game and really adds to the arcade-y feel of the game and makes it more enjoyable.
My overall impression is I rather enjoyed it at first, however it just starts to become too much of a grind, performing the same combos over and over, to be able to hold my interest for long.