A game I would create would be a first person combination dungeon crawler hack'n slash hardcore RPG. What I mean by that is that it would take place primarily in a huge dungeon, complete with small settlements, some friendly (Or at least non-hostile) NPCs, tons of unique monsters, each with their own tactics and abilities. a combat system that is versitile and fun, while still requiring at least something resembling basic intelligence on the part of the player. (Get out of the fire!!! Block the damn attack noob!) NPCs would most likely barter for items rather than having a set price for goods and services, and could become hstile if the wrong things are said to them. (Just like real people) Some NPCs would have influence over others. Like if Bob the sorceror was attacking you last time you saw him, and you left him alive.. Talking to Xanzibar the Archmage might help smooth things over with Bob (Did you REALLY need to insult his mother? Go apologize!) The environment would of course, be as 3d as it could be, without taking away from gameplay and storyline. (It doesn't need to be pretty, it's a dungeon!)