This paper reports on work in progress on the creativeproject MagNular, part of a wider practical study of thepotential collaborative compositional applications of gameengine technologies. MagNular is a sound toy utilizingcomputer game and physics engine technologies to createan animated interface used in conjunction with an externalsound engine developed within Max/MSP. The playercontrols virtual magnets that attract or repel numerousparticle objects, moving them freely around the virtualspace. Particle object collision data is mapped to controlsound onsets and synthesis/DSP (Digital SignalProcessing) parameters. The user "composes" bycontrolling and influencing the simulated physicalbehaviors of the particle objects within the animatedinterface.