Virtual game controllers are essential for particular game genres where the game contents are transplanted from various platforms into a smart-phone platform. Virtual images are projected as a game interface at the smartphone's output screen. Therefore, a certain amount of space needs to be abandoned for the controller's interface projection. In addition, the functions of the game contents are fundamentally limited, thus eliciting the necessity of a limited number of buttons. In this study, diverse types of interaction that occur between the user and touch-screen were researched, and adequate interactions for smart-phone game contents were extracted and analyzed. In addition, the focus is placed on minimizing the number of controller buttons while including diverse functions at the contents level. Notably, the study pointed out that previous virtual game controllers are a mere metaphor of traditional methods, thus limited to Tap interaction. By analyzing fighting action game contents, the Tap interaction is enhanced by adding Flick and Multi-touch interaction to diversify and enhance previous interaction values. Finally, a prototype was developed by ameliorating past interfaces and referring to the intrinsic features of the aforementioned types of interaction, followed by user evaluation. A previous questionnaire method was adjusted to the particular research purpose, and quantitative evaluation was conducted while documenting and analyzing the user-log data of repetitive experiments.
The results show that Flick and Multi-touch interaction techniques are beneficial under a smartphone touchscreen environment beyond the traditional Tap-only. Furthermore, functions are maintained with a minimum number of buttons while the situation compatibility of user interaction is verified. This study also shows that adding diverse types of interaction to the simple Tap-only affords a distinctive user experience of long-term interest and fun to the players that were previously restricted to the accustomed Tap-only. The results authenticate the applicability of the intrinsic fun mechanism to the smartphone based touchscreen game interaction. The study has implications in enhancing the traditional Tap-only based virtual game controller, which is a mere metaphor of controllers loaded onto other platforms, through proposing a tailored interface design and evaluation method under a smartphone platform. Furthermore, this study contributes objective reference source for the engineers to design future game contents, interface and heuristics evaluation in the platform.