a positively massive MMORPG that focused on more building, exploring and exploiting the world then just killing eachother (which is a noticeably large part of the game anyway) that used real-time physics, a battle (and movement) system entirely based around manipulating your player's movements rather then just 'attack attack attack', came up with new ideas, mechanics, materials, artifacts and areas on-the-fly, used context-sensitive buttons to cut down on the MASSIVE amount of commands needed, allowed players to come up with new ideas on-the-fly using an ingame shape creator that essentially allowed you to beat, carve, trim, paint, etc pre-existing objects like metal bars and wooden shafts into more interesting or useful shapes, like for instance smashing a metal bar into a bland 'ol shortsword or a hyperintricate piece of work that would scare most people stuffless just to look at
also no lag