Charles L. Mauro, “Why Angry Birds is so successful and popular: a cognitive teardown of the user experience” (2011)
What makes a user interface engaging is adding more detail to the user’s mental model at just the right time. Angry Birds’ simple interaction model is easy to learn because it allows the user to quickly develop a mental model of the game’s interaction methodology, core strategy and scoring processes. It is engaging, in fact addictive, due to the carefully scripted expansion of the user’s mental model of the strategy component and incremental increases in problem/solution methodology. These little birds are packed with clever behaviors that expand the user’s mental model at just the point when game-level complexity is increased. The process of creating simple, engaging interaction models turns out to be exceedingly complex. Most groups developing software today think expansion of the user’s mental model is for the birds. Not necessarily so.