I worked on Crush the Castle for Armor Games in the late 2000s. Angry Birds took the same game concept, added much cuter characters and art, and blew us out of the water with it. (No offense: we took it from someone else.) Now I feel kinda sad, kinda smug that their glory is fading a bit. Rovio seems to have forgotten the lesson that the greater your success, the more likely you are not to be able to repeat it. People tend to assume their best days are ahead, and thus expansion proves to be overexpansion when the best days turn out to be behind.