Interactive narrative is a blossoming field, with new systems and approaches being developed each year. However, despite this burgeoning array of designs, little work has been done in empirically evaluating and comparing them (Weyhrauch 1997; Nelson and Mateas 2005; Magerko 2007). Such a comparison is complicated by the fact that different systems are used to create different narratives; it is difficult to differentiate between the authored content and the system capabilities in an empirical setting. This paper proposes a comparative analysis approach to determining the strengths and weaknesses of interactive narrative systems. Such a comparison is a positive first step towards understanding and evaluating current and future interactive narrative systems.