This article deals with serious game design methods. More specifically, it focuses on the following question: is there any universal series of steps to design a serious game? Or is the availability of several different design methods unavoidable? To try to answer this question, we will study a corpus of ten design methods suited to Serious Games. Most of these theoretical tools are coming from or aimed to industry professionals. This literary review will allow us to perform a comparative analysis over the various steps used by these methods, in order to build a generic model for the design process of Serious Games: the "Design/Imagine/Create/Evaluate" (D.I.C.E.) model.