A systematic single case study with a mixed quantitative and qualitative methodology was conducted to investigate the nonlinear dynamics of change in play profiles of a child in psychodynamic play therapy. The first aim of the study was to cluster the different features of play characteristics (i.e., descriptive, cognitive, affective, and social characteristics of play, and the defensive strategies used in play) in order to construct the different play profiles of this child, and secondly to assess the transitions between profiles over the course of treatment. It was expected that there would be an increase in critical fluctuations during the transitions between the profiles and an increase in the variability of play profiles. Results showed that the child's play characteristics clustered into eight states and three attractors. The Markov Transition Matrix showed how play profiles evolved over time. Entropy analyses comparing the first and the second half of therapy showed an increase in variability. Qualitative analyses indicated the importance of expression of the child's underlying fear, and its integration with overt anger in the generation of the new play profiles. The results indicate an increase in variability, and a destabilization of old play profiles that were used towards generating new play profiles.