Very nice work. Would each moving element have its own characteristics e.g. in object orientated programming (OOP) it would have a x position, y position, direction, magnitude. Then various functions to make those move based on the tilt sensor reading and to impact and bounce off each other/the sides.
Its a particle system (https://en.wikipedia.org/wiki/Particle_system ). 14rb summarizes it well, each particle has its own attributes, and at each time unit they are updated according to classical mechanics. There are a couple of particle system apps in the android store you may want to check and play with.
Are you willing to share your build of materials for hardware and software.
I would like to share it with my grand daughter. Imitation is the sincerest form of flatter. A hardware list, software list and sharing your code is what I am looking for. Suppliers for your parts would be ideal.
