I would recommend expanding this game by adding scenery for the player to hide inside or navigate through, and since it fits theme you used, perhaps you could research an old game called Micro Machines about ideas for your scenery? Collision detection is something you may have to code yourself, but perhaps Unity can do this for you, and also make the scenery movable with physics or even destructible? Creatively if it was me, I would start by testing chocolate squares as walls or sets of pillars and go from there.