In Hong Kong, play-based learning has been highlighted in the latest curriculum guide in 2017. While adopting 'child-centredness' as the core value of kindergarten education can enrich children's play experiences. However, little emphasis has been placed on how young children perceive play-based learning in the classroom. The aim of this qualitative research is to reveal young children's unique perceptions of what play means to them. Data were collected through non-participant observation during delivery of a play-based learning curriculum in class and post-observation focus group interviews with the children whose classes had been observed. An interpretive method is employed to divulge their perceptions. Cross-analysis of the observation data and the children's statements shows how the children perceived "play" and how they determined "playfulness." Combining data from interviews and classroom observations, findings reflected the lack of consistency between what children described as play and how teachers practiced play-based activities in classes. This study evoked the concern for teachers in making developmentally appropriate pedagogical choice to engage children in learning through play. The importance of respecting children's feelings about playfulness and teachers' role in ensuring quality learning experiences is discussed.