The paramount importance of studying very high-energy (VHE) astronomical phenomena is straightforward for the scientific community. Conversely, it might be difficult, for both the general public and school students, to grasp how much information can be encoded in electromagnetic emission invisible to our eyes. On the other hand, it is fascinating to describe how our Earth’s atmosphere can be exploited as an instrument to intercept the highest energy photons that can be studied today, via the Cherenkov emission of particle showers. To this aim, a dedicated group has been established within the Italian Istituto Nazionale di Astrofisica (INAF) since 2020, in order to foster Public Engagement for two Cherenkov Telescope projects: ASTRI, an INAF-led project, and CTAO, an international observatory in which INAF is a major contributor. The group, known as INDACO (INaf for the Dissemination of Astri and Cta Observatory), has a vast repertoire of activities. We will focus here on a case study: a laboratory dedicated to primary and middle school pupils based on “learning-by-doing” and “education through play”. The game consists in reconstructing the multi-wavelength image of the well-studied active galaxy Centaurus A by solving challenges and riddles in order to gain the additional information and material. By playing with the different emission bands, the role of the VHE one becomes clearer. We present the design of the activity, together with feedback and lessons learned of this pilot project. We extrapolate our experience to the fields of outreach in the astrophysics of the invisible Universe.