This study first analyzed how online gamers differ from non-gamers in terms of lifestyle, and further examined how online gamers can be segmented based on lifestyle and what their characteristics are. Specifically, the study empirically investigated how each segment differs in terms of demographics, spending on online games, and the relative importance of factors contributing to loyalty formation. Additionally, by identifying the requirements of each online game segment, the study sought to determine what consumers within each segment desire and, consequently, what kinds of games should be developed. The results revealed that, contrary to conventional belief, online gamers are not reclusive individuals who fail to lead normal social lives; rather, they tend to be sociable, pursue progressive fashion, and engage in active cultural activities. Furthermore, lifestyle-based market segments of online gamers could be broadly classified into "family-centered active type," "sociable leader type," and "fashion and extroversion-seeking type." Important commonalities and differences were found across various dimensions for each segment. Examining the factors influencing gamers' game loyalty, it was found that gamers prioritize flow factors, social interaction factors, and sales promotion factors, in that order. However, there were some differences across segments: for the "family-centered active type," social interaction, support services, and first-mover effects had a greater influence on online game loyalty compared to other clusters, indicating that marketing activities are important for enhancing the loyalty of the family-centered active type.