To enhance the effectiveness of educational games, researchers have advocated adding learning supports in educational games, but this may come at the cost of disrupting the learning experience. Embedding virtual companions to provide learning supports may be an effective solution that naturally integrates learning supports into the game. However, the effects of virtual companions providing learning supports (VCPLS) and potential influence mechanism are deficient. This study investigated the efficacy of VCPLS in enhancing learning experiences and performance in comparison to the system providing learning supports (TSPLS) and explored how VCPLS played a role in improving learning performance. A single-factor (VCPLS/TSPLS) between-subjects design was employed, and four similar-level classes (126 middle school students) were randomly assigned to the two conditions. The results revealed that compared with TSPLS, VCPLS promoted learners' basic psychological need satisfaction, positive emotions, motivation, and perceived learning performance but there was no difference in transfer performance. VCPLS also encouraged students to spend more time reading explanations and feedback, and process explanations actively after the first attempt and before the second attempt. Moreover, VCPLS promoted perceived learning performance by the mediating role of basic psychological need satisfaction and the sequential mediating roles of basic psychological need satisfaction and motivation.