Fostering English reading interest and engagement among young learners in non-native settings demands innovative strategies. Previous studies emphasized the role of teachers in enhancing reading interest, for example, through dialogic reading due to its interactive nature. However, this approach is challenging to implement on a large scale. Lately, the emergence of the metaverse has brought new affordances for education. This study attempted to integrate paper storybook reading with metaverse interactivity to boost students' reading interest. It proposed a gamified metaverse design to merge gamification with metaverse elements, thereby enhancing reading experience. This virtual space allows students to engage with story-related interactive objects and story chatbot non-player characters (NPCs), facilitating story reflection through natural dialogues. Through a quasi-experimental design, the study contrasted the reading interest and engagement of a control group with 47 elementary school students engaged in silent self-reading with those of an experimental group with 46 students interacting within the gamified metaverse. The results indicated that the experimental group significantly outperformed the control group in terms of reading interest and engagement, highlighting the gamified metaverse's potential for fostering reading interest. Additionally, the study identified four distinct learning patterns within the gamified metaverse, and analyzed their navigation patterns. The analysis revealed the affordance of the space to support diverse learner needs by enhancing competence, fostering a sense of relatedness, and supporting autonomy. The study suggests that the autonomy provided by the self-exploration space and the learning support by the chatbot NPCs in the gamified metaverse positively impact students' reading interest. The study provides data-driven insights into the behaviors associated with reading interest within the metaverse.