Requires:

{
  "or": [
    {
      "enemyKill": {
        "enemies": [
          [
            "Beetom",
            "Beetom",
            "Beetom",
            "Beetom"
          ]
        ]
      }
    },
    {
      "obstaclesCleared": [
        "A"
      ]
    }
  ]
}

Clears obstacles: A