Straylings Oldhaven – an educational mobile app – is beyond a learning game; it is a mastery game. It builds fluency in competency skills required to reduce cognitive load when tackling problem-solving tasks. In the game, levelling up requires the completion of an earlier task through repeated trial and error attempts. Children learn through continuous small improvements, and that becomes a learning strategy they take forwards with them. They develop a mindset that failure is an inevitable part of the path to discovery.