Research on gamification of advertising concerning subtle design elements of computer games and their effects on consumers’ psychological responses are limited. The present research addresses this gap by examining how consumers’ attention and memory of brands advertised in a game, popularly called in-game advertising (IGA), are positively affected by the type of the gaming platform (mobile vs. PC) and rule orientation (or game rules) in the presence of potential moderators such as interactivity with the ad and congruence between the ad and game’s goals. Two experimental studies are conducted that investigate these afore-mentioned effects. The results indicate an interaction effect such that rule enactment under high ad interactivity and high ad–game goal congruence increases attention and memory of ads in mobile-based IGAs. Further, these affects are mediated through media and ad transportation, that is, players’ immersion experience in the flow of a story while playing the game. The research advances past knowledge on advertising effectiveness in computer games by exploring a less studied area, that is, the independent and interactive effects of game design elements. It also contributes to the flow experience literature in the domain of gamification by revealing a sequential pathway involving media and ad transportation. Also, it adds novelty to the gamification literature by exploring the role of gaming platforms and their interaction with design elements. For the game developers and advertisers, the research provides strategic guidance to manipulate these elements and to choose suitable platforms for the purpose of maximizing consumers’ favorable psychological responses.