In this study, we developed a game-based learning system on a social network platform to instruct customs and cultures in the English speaking countries in order to investigate the increase of learning willingness and motivation by using the digital game-based learning(DBGL) model. To determine the learning behaviors and results of the learning design which combines game-based and social network theories, this study involved students from an elementary school to implement a multi-player, real-time quiz game, known as 'Challenger', on the Facebook platform. As players, the learners can "Call Out" for help or assistance; however, online friends hold the decision of "Replying" or "Not to Reply" the players' "Call Outs". This mechanism is so called "Peer Feedback". Results of this study showed that the DGBL incorporated into a social network website is a feasible and sound model for teaching. By the model, English learning will become more interesting which makes students more enjoyable in learning auxiliary materials after school if they cannot fully comprehend the course in the classroom. By the outcome, we found peer influence seems not only motivates learner's participation in the game but also catalyze learning effectiveness.