The concept of child-friendliness has appeared in numerous research studies concerning sustainability and the wellbeing of children. For this critical review of child-friendly environments (CFEs), an evaluation framework of CFEs has been developed, consisting of four principal experiential categories: sociality, wellness, development, and independence of children. Despite considerable research on CFEs since the middle of the twentieth century, there have been few evaluations of CFEs focusing on children’s experiences in relation to the physical environment. Through an exhaustive analysis of selected papers in this research, it was found that most papers have focused on the physical experiences of children, rarely mentioning the emotional experiences of children in relation to the physical environment. The environmental experiences of children are very critical for a balanced development in their emotional, physical, and intellectual comprehension. Therefore, research on CFEs should consider the balanced emotional, physical, and intellectual development of children. This research critically highlights the aspects of children’s experiences to be addressed in CFEs research, exploring valuable insights into the environmental cognition of children and their development. A better understanding of children and an interpretative analysis of their experiences will lead to adequately balanced CFEs, creating sustainable environments.