This presentation highlights a study on the interactive design and implications of a playful co-creation tool, Comicubes, which combines a two-dimensional blank cardboard canvas with a three-dimensional, open-ended toy medium: the cube. In our study, we tested the concept's functionality as an ideation tool suitable for different target and age groups, as well as its potential as a creative physical platform that encourages design thinking, allows for playful manipulation, and invites interaction. In workshops designed for preschool-aged children, participants were asked to create a plaything of their choice by applying various art supplies to blank cardboard cubes. The workshop findings indicate that the children in our test group, as digital natives, were able to use the Comicubes platform to co-design and create a physical plaything and develop associated play patterns and open-ended (toy) or rule-based (game) ideas for its use.