{
  "stage":
  {
    "left":   0,
    "right":  0,
    "top":    0,
    "bottom": 0
  },

  "balls":
  [
    { "img": "tux", "r":  25, "x": 100, "y":  50, "vx": 200, "vy":  17 },
    { "img": "owl", "r":  25, "x": 150, "y": 150, "vx": 100, "vy": 217 },
    { "img": "tux", "r":  25, "x": 200, "y": 250, "vx": 250, "vy": 117 },
    { "img": "owl", "r":  25, "x":  50, "y": 100, "vx": 200, "vy": 213 },
    { "img": "tux", "r":  25, "x": 300, "y": 400, "vx": 202, "vy": 100 }
  ]

}