• Inside3 is a maze hidden inside a cube. • We play blindly with the help of the map engraved on the surface. • This model is detachable: we can find the little ball when it's lost and see the insides of the cube. • It contains a second ball enclosed in a secret area (Phantom) that complicates the task of playing by blurring auditory references. • Difficulty level of this model: 7/12.