This mixed methods study examined the effectiveness of a virtual world curriculum for teaching elementary students complex science concepts and skills. Data were collected using pre- and post-content tests and a student survey of engaged learning, An additional survey collected teacher observations of 21st century competencies conducive to learning. The study involved a five-day intervention of fifteen 4th grade students in a small Midwestern school using a virtual science computer game from Arizona State University. Thirty elementary teachers from Australia, England, and the United States were surveyed on classroom observations of their elementary students working in the virtual world environment. Research questions guiding the virtual learning study were: (1) do pre- and post-content tests show significant learning in the virtual environment; (2) are students academically engaged during the learning process; and (3) are students actively demonstrating relevant 21st century competencies. The study supports prior research in game-based learning showing measurable learning results, highly engaged, motivated students, and observations of student behaviors conducive to learning science in school, namely collaboration, problem solving, critical thinking/inquiry, global awareness, and technology use.