Education plays an important role in nurturing children. COVID-19 pandemic brings challenges or disruptions to school education, due to school closures in some countries. Science subject in primary schools is unique as hands-on experiments are important learning components. Its learning process may be affected, as a new norm of online learning or home-based learning. This research project creates a serious game on science subject for primary school students aging within 10 to 11 years old using virtual reality (VR) technology. It consists of three virtual learning phases. Phase 1 explains theories of science topics on electricity and electric circuits. Phase 2 provides interactive hands-on experiment exercises where students can practice theory knowledge learned in the previous phase. An interactive quiz session is offered to reinforce the learning in Phase 3. Interactive VR features enable primary school students learning abstract science concepts in an interesting way compared to conventional classroom settings. Meticulous design attentions have been placed in the details such as visual instructions, voice instructions, speech tempo, animations, and colorful graphics to create a sense of realism and keep students actively engaged. Preliminary case study has been conducted with 10 students at primary schools in Singapore to evaluate learning effectiveness in this research.