Playability, simplicity, and atmosphere. Maps need to be easy to play. Having to do 50 things in the inventory just to use one spell sucks. The game is good if it has a certain atmosphere.
I'm gonna get a little bit sidetracked here and not talk about starcraft... Sports game dominate the category of replayabibility, if it's madden or ncaa you would want to play it forever unless a newer one comes out!