A large set of pathologies can make it impossible for several users to use an OS (Operating System) or a software. In fact, most User Interface (UI) are developed around WIMP (Windows Icon Menu Pointer) interfaces while Post-WIMP interfaces are not yet widely used. While consoles designers have started to include this paradigm in their products and have a long history on ergonomic studies, most of these approaches are not exploited to give the opportunity to disabled people to use a computer or a game console. In this paper, we present the first step towards a multimodal interaction approach for designing therapeutic games. This approach is conceived to work in conjunction with a game for all design. This means that not only the game has to be usable by regular user and disabled people but also that the conceived game has to be fun for both targets. In this paper we present a first set of interview we conducted with four therapists. These interviews allowed us to present a first solution to use several devices in order to deal with different pathologies (i.e. a multimodal approach) that we applied to a cross platform game.