Abstract: A rolling toy assembly that has a hollow body. The hollow body has an interior and a bottom surface with an open window that accesses the interior. A spherical mass is disposed within the interior of the hollow body. The spherical mass is too large to pass completely through the open window. An eccentric weight is coupled to the hollow body. The eccentric weight biases the hollow body into a tilted position wherein the bottom surface and the window are tilted at an angle of inclination. This enables the toy assembly to roll over small obstacles. A play platform is provided. The play platform has a top surface that defines at least one concavity. The concavity is surrounded by a peripheral rim bump. The toy assembly is placed on the play platform and is caused to roll by manually manipulating the play platform.