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

  "balls":
  [
    {
      "@count": 7,
      "img":    [ "@some", "tux", "owl" ],
      "r":      { "@min":  50,  "@max": 75 },
      "x":      { "@min": 0.05, "@max": 0.50, "@relative": "horizontal" },
      "y":      { "@min": 0.15, "@max": 0.25, "@relative": "vertical" },
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      "vy":     { "@min":  10,  "@max": 400 },
      "ax":     { "@min": 200,  "@max": 600 },
      "ay":     { "@min": 200,  "@max": 600 }
    }
  ]
}