Pros
Supercell provides the freedom to get the job done without any red tape or egos. If you want a place where you can actually execute a plan - this is the place. Along with freedom comes responsibility which most overachievers seek out in a career. It is a great opportunity to sink your teeth into a role, get things done the right way and to truly focus on Quality. One of the most collaborative environments I have ever seen...with out the territorial politics.
Cons
Not a con for those who seek independence - but there is very little hierarchy so no one tells you what to do or exactly how to do it. It is up to you. If you are confident, passionate and like to be in control of your job you will love it at Supercell. If you want direction and to be told what to do and how to do it, you probably won't thrive in this environment.