The main features of Underworld are both new and familiar as listed below:
Underworld: When a character dies in the Underworld MMO, their "soul" journeys to the Underworld of their particular Realm of Mythology. Greek charaters go to Hades, Norse characters go to Valhalla of Hel.
A character has to work their way back to the land of the living. They gain valuable experience from the journey. howeve, characters such as Vampires, who have no soul, suffer permanent death(permadeath) if they are killed. Even major NPCs go to the Underworld when they die.
Technology: A lot of technology is only usable by humanoids. Tetsus are an example of this.Some technology is only usable by inhumans. Vampires are an interesting exception because they can use both human and inhuman technology. Of course, they pay the heavy price of permadeath for this luxury.
Weather: Weather exists like in other MMORPGs. In Underworld MMO it can affect things beyond visibility. Ranged weapons have decreased range and accuracy, certain creatures have lessened or heightened abilities in certain weather. Some creatures can even be destroyed by weather(Vampires and Sunlight comes to mind).
In addition to these elements, magic users can actually control the weather on a zone by zone basis and use it?s affects against their enemies. Should two wizards have a duel in underworld MMO, it is a sight to behold.
Uniques: Rare item in Underworld MMO are truly UNIQUE. There is only ONE Majolnir, hammer of Thor and every other rare item. Should a major NPC lose their main weapon. They will seek it out from the ones who stole it. Should they be unsuccessful in retrieving it, they will have a new weapon made, but it will not be the one they lost. Be wary of players who learn that you have the Unique they seek!
Misc: In addition to human controlled NPCs, a lot of the elements of Under world MMO are familiar to MMORPG players. They are implemented a little differently:
Guilds: Can create their own quests, own property and AI stores.
Pets and Deities: Can be invoked, evoked or created (Golems)
Transportation: Walk, run, fly, swim, teleport or use vehicles and mounts.
Races: Over 20 races in the game are playable. Even monsters.
Servers: No mirrored duplication here. Thousands of players, One world. We add new Realms of Mythology to support additional players. There are enough mythologies on Earth to support half a million players in one huge gameworld.