I need a comprehensive literature review on the role of play in digital learning, targeting middle childhood (6-12 years) and adolescents (13-18 years). The review should focus on cognitive development, social interaction, and engagement and motivation. Requirements: - In-depth analysis of both empirical studies and theoretical perspectives - Coverage of the specified age groups - Insightful exploration of the three focus areas Ideal Skills and Experience: - Expertise in educational psychology or digital learning - Strong research and analytical skills - Experience writing academic literature reviews - Familiarity with current trends in digital learning and play