Sound toys are game-like technologies that can be described as playful sonic interactions where the users are given unusual ways to creatively explore and transform synthetic sound. This study investigated the prototyping and evaluation of a new sound toy. The toy was designed to test new possibilities for playful music interactivity and sonic exploration. Inspired by prior sound toy research, the design utilized game data, such as user input and simulated physics, that were mapped to control FM synthesis parameters. As intended by the design, the means of controlling the sonic parameters were not obvious to the users, but the sound synthesis was controlled by the movement and collision of virtual objects. The sound toy was evaluated through User Experience (UX) testing which provided a detailed assessment of the interaction design. In general, respondents associated the toy with puzzle-like interactions found in games. Respondents reported that the interactions were fun, intriguing and accessible. Findings confirmed that the playfulness of the experience and the sense of being in control was not dependent on the users understanding the input mappings to the sonic parameters.