Crouch jump up through the left side of the door transition. Angle up and shoot the fish twice on the way up, then aim down and shoot three more times as needed until it is frozen. Land on the fish, wait until it is flashing, then jump and freeze it again further to left as needed, until you can spin jump to the left to reach the platforms.

Entrance condition:

{
  "comeInWithPlatformBelow": {
    "maxHeight": 7,
    "maxLeftPosition": 2,
    "minRightPosition": -2
  },
  "comesThroughToilet": "any"
}

Requires:

"canCrossRoomJumpIntoWater"
"canCrouchJump"
"canTrickyUseFrozenEnemies"
{
  "or": [
    "Wave",
    "Spazer",
    "Plasma"
  ]
}