Pros
It is great when it is great. Lots of food provided, activities after-hours many days a week, "unlimited vacations," jams, etc. CEO is very active in the startup community. If you are willing to accept the company direction of the moment, there can be opportunities to climb the ladder in a short amount of time. Compensation is high as well, although you will be working long hours and weekends for it (though that may be good for some types). They also tend to seek and get a lot of press.
Cons
Turnover is extremely high (ie several people a month), both due to employees frequently leaving for places with more opportunities for growth, or firings. Most hires are gone after a year or two, if not months. Expectation of long work hours and a cult-like attitude. The company vision seems to shift frequently... it used to be a company called Game Closure and was rebranded to fit the most recent shift. Management can be inspirational at times, but can also be fickle and hard to dialogue with. Production cycles have ill-defined goals with no followthrough, and a lot of wasted effort. Can be very frustrating. Overall would not recommend to a friend as there are many more stable places to work at.