Zekkyou on 02 March 2015
I don't believe any part of a game is inherently the "most important", but it is important that each part (regardless to how limited) is presented in a manor that doesn't take away from its focus.
Titles like Heavy Rain work because while the gameplay is very simplistic, it does a good job of presenting its core strengths. If the QTEs were clumsy and poorly timed, i'd lose some interest in the story since an unnecessary obstacle had been put in my way. The reverse is often true too, as are many other combinations.
