Pros
Great benefits and a casual atmosphere. Great gym in the building next door. Quite a few team outings that are fun and to cool places.
Cons
I found it difficult to climb the ladder at Nexon. It seemed as if you were at least making it seem like you were busy, staying late as much as possible (even though there may not be anything pressing to handle), etc., that was seen as productive and a way to look good in the eyes of upper management. I saw micro managers move right up and it seemed to be due to their overall apparent stress level, willingness to constantly work late (needed or not) that made them appear to be steering things in the right direction. Then there were other employees who quietly got things done in a much more efficient manner and didn't need to work late five days a week that got pushed aside.