Pros
There are some genuinely good people working there and some genuinely A+ talent there. Some interesting engineering problems dealing with scale and availability. Fast-paced - you will get a great many projects to work through and it will be frantic and often fun and rewarding. If you are not too pushed or if you really don't care that much about good practice in software development, this could be the place for you. Pay is good, increments and promotions are regular and there can be a good vibe and social aspect to the office (nerf guns, beers etc.)
Cons
Cowboy-coder shop. Do not work here if you are a serious software engineer who cares about any of the advances in the industry in the last 10 years or if you enjoy basic standards or practices that are common elsewhere such as not repeating code or unit testing (yes, really). Incredible amount of poor code and technical debt. This is passed off as "moving fast", "like Facebook" or "taking risks" with no repercussions. If they think that is how Facebook go fast and break things they are very misguided. Some promotions are deserved, most baffle. Bad, messy coders end up leading teams, non-technical people with no good people skills made Engineer Managers. C-level execs are for the most part good people but they are scuppered by the CEO who switches focus every few months based on whatever TechCrunch article was read that morning. The execs seem to get very little detail or fully thought out plans but then have go ahead and steer the company. There is no real vision or innovation. Just copying the flavor of the month and hoping you get lucky. Core business is PC download games but industry has moved on and left that behind.