Original entry :) Apart from the texture on the ground (or whatever other graphical indications of movement, even velocity-specific 3d particles would make this more spatially communicative) I would add some indicator of battery location maybe as one of other commenters also said, and for sure for police (even the larger radius of hearing the sirens would be good, right now you can only hear them when you already see the police vehicle and it's very close). It is a nice prototype, engaging and giving fun, I liked it :)