I have been playing Materia Magica for several years, from the time when it was known as Moongate.
This game can be played in a variety of styles, from aggressive player-killing to extensive exploration to power leveling.
The class system is based on four types and you choose a path based on race and skills. Certain combinations are favoured over others, since some skills and spells overlap.
The prompt is very easy to read, with an organized layout and colour coding. Navigation is simple, with a compass in the top right corner to point out directions.
The Immortals are active in the upkeep and development of areas, but for general help, there are detailed help files and friendly Guides to assist.
The Guides are actually volunteer players who donate their time to help those who need extra assistance.
The world is called Alyria, and in addition to the main part of the world, there are also two alternate planes of existence: The Underground and the Faerie Plane.
Each of these areas encompasses thousands of rooms, creating the genuine feel of great distances that must be crossed to reach a goal.
The arena system allows players to challenge other players directly from almost anywhere in the world.
The auction system allows players to sell equipment from almost any location, and pick up the item at the nearest post office.
The quest system gives rewards for following a set of phases, and gives quest points which can be redeemed for elite equipment.
Players can navigate the seas as a passenger or with their own boats.
The most important part of the game is socialization, through interaction with other characters and through the chat systems. There are players from all over the world with whom you can talk and play with.
I highly recommend visiting the world of Alyria in Materia Magica.