This is a really good game, Mushpoie is a good server (needs more people from JSP on it xD)
This game introduces a lot of new things from MMORPG's, such as the flying, the skill/jobs system, etc. However, this is only out of the MMORPG's that I have played (i've played about like 13 different ones)
Also, it uses and expands on already existing features of MMORPG's such as have item level system (for example, a long sword +6). Another thing about the item level system is that it can increase if you use a certain item (in this game it is called a sunstone) on it. Also, at a certain level, the item starts to glow. This game also has an item element system, which is similar to the item level system, only instead of just increasing the item attack/defense of the item, it increases the elemental defense/attack of the item.