The next steps to implement, ordered by level of urgency
will be the following:

    (a) ensuring agents do not get stuck on geometry
        during the simulation
    
    (b) ensuring agents are properly spawning during the 
        simulation after the first time step

    (c) making agents in visualization have the correct
        size based on their assigned radius

    (d) colouring agents in the visualization based on
        which grade they are assigned