12

It is much more common for Ridley to hit Samus when Ridley is facing left. One way to get Ridley to turn around is when it pogos on the right side of the room, stationary spin jump and break spin. The fireballs can be tricky to deal with in the door frame, but can be done by dropping down and quickly wall jumping back up or by kagoing them.

Requires:

{
  "heatFrames": 900
}
{
  "or": [
    "canTrickyGMode",
    {
      "heatFrames": 180
    }
  ]
}
"canComplexGMode"
{
  "or": [
    "SpaceJump",
    "canWalljump",
    {
      "and": [
        "HiJump",
        "canSpringBallJumpMidAir"
      ]
    }
  ]
}
{
  "not": "f_DefeatedRidley"
}
"canRiskPermanentLossOfAccess"

Exit condition:

{
  "leaveWithGModeSetup": {}
}

Dev note: Not likely to be possible, as it requires canRiskPermanentLossOfAccess and Ridley alive with the door unlocked. The extra heat frames are a leniency to account for randomness.