{
  "schema": 2,
  "id": "L1_mouth",
  "name": "Oral Cavity",
  "tagline": "Learn to swim",
  "seed": 20260701,
  "par": { "time": 300, "score": 2500, "samples": 3 },
  "next": "L2_esophagus",
  "design": {
    "owner": "Lane C",
    "status": "AUTHORED (round 3). The skeleton waited on 'Lane B's arena-mode controller' and that now exists, so the round2_plan below is built: molar crush-cycles, saliva tide, amylase droplets, the three samples where C put them, and the epiglottis exam.",
    "identity": "The tutorial, and the only level that is mostly arena. Teaches move / look / shoot / coat in safety - and then, at its centre, teaches the thing the whole game is about, which is that not everything in here is your enemy.",
    "anatomy": "Vestibule (outside the teeth) -> oral cavity proper (the arena, ringed by molars) -> oropharynx, narrowing to the epiglottis gate.",
    "biome_note": "biome = tissue/look family (Lane A's registry), segments[].name = the anatomy. There is no 'pharynx' biome and there should not be: the oropharynx is deliberately given the ESOPHAGUS palette so the tube turns teal as you approach the epiglottis. The colour shift is the wayfinding - it tells you where you are going before the gate does.",
    "scale": "Real oral cavity is ~8cm across; arena radius 90 units = 18cm diameter. Dilated ~2x - much less than L2's 14x, because arenas need room to fight in and the mouth is already a room.",
    "teaching_order": "move (orbs, no current) -> LOOK (the arena opens, and in 6DOF you can stop, which no other level lets you do) -> shoot (one droplet, then two) -> coat (the molar ring grazes you, mucin is right there) -> RESTRAINT (the mast cell) -> flow returns (the tide, then the funnel) -> the exam (the epiglottis). Every verb is taught alone, in the calmest room in the game, before anything is asked of it.",
    "why_the_mast_cell_is_here": "A tutorial teaches verbs; this one also has to teach the THESIS - the body is weather, and the immune system is not evil, it just cannot tell what you are. The Mast Cell is the only encounter in the game you win by holstering the gun, and it is placed at the exact midpoint of the tutorial so the lesson arrives before L2 shows the player their first cyan flora colony. A player who shoots it does not fail: they get the cascade, they get through anyway, and they have learned it the way that sticks. Spec: LANE_C_NOTES §Boss specs 5.",
    "checkpoint_density": "Nine checkpoints in 720 units, which is the densest in the game and looks absurd next to L2's ten in 3600. It is not: flow here is 2 u/s (C's 'the only place where nothing is pushing them'), so the 30s death-cost law works out to ~69 units per checkpoint. A slow room is a forgiving room and this is the tutorial - the law and the level agree for once.",
    "par_rationale": "300s is the honest traversal at flow 2. par.score 2500 is sized to the pacifist route: 3 samples (1500) + the orb lines + the droplets that are actually meant to be shot. Killing the mast cell scores NOTHING, so the score medal can never reward the mistake."
  },
  "segments": [
    {
      "biome": "oral",
      "name": "Vestibule",
      "length": 120,
      "radius": { "base": 14, "wobble": 0.1 },
      "curviness": 0.1,
      "flow": 2,
      "note": "Injection point. Almost no current - the player's first 120 units are the only place in the game where nothing is pushing them anywhere."
    },
    {
      "biome": "oral",
      "name": "Oral Cavity",
      "length": 400,
      "radius": { "base": 30, "wobble": 0.2 },
      "curviness": 0.15,
      "flow": 2,
      "note": "The arena (see arenas[0]). 6DOF unlocks here. Molar crush-cycles ring it; saliva tides sweep it."
    },
    {
      "biome": "esophagus",
      "name": "Oropharynx",
      "length": 200,
      "radius": { "base": 12, "wobble": 0.2 },
      "curviness": 0.35,
      "flow": 6,
      "note": "The funnel. Mode returns to tube and the current starts to build - the game re-teaching flow just before the gate hands the player to L2. Wears the ESOPHAGUS palette on purpose (see design.biome_note): the walls go teal 200 units before the epiglottis, so the player reads the transition in colour before they read it in a HUD."
    }
  ],
  "arenas": [
    { "at": 320, "radius": 90, "biome": "oral", "note": "The oral cavity proper. Spans s 230-410 (sphere of radius 90 centred at s=320)." }
  ],
  "events": [
    { "s": 20, "type": "checkpoint", "name": "Injection Point" },
    { "s": 40, "type": "pickup", "kind": "nutrient_orb", "count": 4, "spread": 55, "note": "TEACH MOVE. The first thing in the game is a line of orbs in still water with nothing to hurt you. It teaches the racing line before it scores anything - the opening contract every level honours, but here it is the whole lesson." },
    { "s": 85, "type": "checkpoint", "name": "Vestibular Fold" },
    { "s": 110, "type": "spawn", "enemy": "amylase_droplet", "count": 1, "note": "TEACH the obstacle. One droplet, drifting, in a 14-unit tube at 2 u/s. It has a corrosive aura and the player has all the time in the world to notice that steering around it costs nothing." },
    { "s": 150, "type": "checkpoint", "name": "Behind the Teeth" },
    { "s": 170, "type": "pickup", "kind": "biopsy_sample", "count": 1, "theta": 0.4, "rho": 0.92, "note": "SAMPLE 1/3 - behind the molars, where C put it. Deliberately the easiest collectible in the game: wall-pinned in still water with nothing chasing, so the tutorial can teach 'these exist and they sit off the racing line' without also charging for it." },
    { "s": 200, "type": "spawn", "enemy": "amylase_droplet", "count": 2, "spread": 45, "note": "TEACH SHOOT. Two of them blocking a comfortable line - the first thing in GUTS the player is actually invited to destroy. That matters, because 120 units later the game offers them something they must not." },

    { "s": 215, "type": "checkpoint", "name": "The Cavity" },
    { "s": 250, "type": "hazard", "kind": "ring_gate", "period": 5.0, "open": 3.5, "warn": 3.0, "note": "TEACH the molar crush-cycle. C's round2_plan asks for crush-cycles on the arena rim; mechanically a periodic ring seal IS a bite, and it is a verb the campaign already owns - so L1 teaches it and L2's gates at s2100/s2800 become a callback rather than a new idea. 70% open with a 3s telegraph at 2 u/s: you clear it without thinking, which is exactly why it belongs here." },
    { "s": 280, "type": "checkpoint", "name": "Molar Ring" },
    { "s": 300, "type": "pickup", "kind": "mucin_glob", "count": 1, "note": "TEACH COAT, immediately after the first thing that can graze you. The economy's law in miniature: the game pays you right after it charges you, and the player learns what the left-hand bar is for by watching it refill." },

    { "s": 320, "type": "boss", "id": "mast_cell", "note": "THE THESIS, at the exact midpoint of the tutorial. A sentinel immune cell on patrol: cyan, no attack, no chase, inert aura. Fly past and the encounter simply ends and the biome thanks you. Shoot it and it degranulates - histamine floods the cavity, droplets close in from the walls, the coat drains twice as fast, and past half health the airway starts closing on a 25s timer. You still get through. You just get through a worse mouth, and you made it. Spec: LANE_C_NOTES §Boss specs 5." },

    { "s": 345, "type": "checkpoint", "name": "Tongue Base" },
    { "s": 370, "type": "pickup", "kind": "nutrient_orb", "count": 3, "spread": 45 },
    { "s": 410, "type": "checkpoint", "name": "Sublingual" },
    { "s": 430, "type": "pickup", "kind": "biopsy_sample", "count": 1, "theta": 4.71, "rho": 0.85, "note": "SAMPLE 2/3 - under the tongue, where C put it. Costs a detour to the floor of the cavity while the arena's 6DOF is still novel: the first collectible that asks the player to use the freedom they were just handed." },
    { "s": 450, "type": "spawn", "enemy": "amylase_droplet", "count": 3, "spread": 65, "note": "TEST the droplet: three at once, in the open. Everything taught so far, with room to fail safely." },

    { "s": 475, "type": "checkpoint", "name": "Faucial Arch" },
    { "s": 500, "type": "hazard", "kind": "reflux_surge", "speed": 5, "from": -30, "span": 140, "warn": 3.0, "lethal": false, "note": "THE SALIVA TIDE (C's round2_plan). A slow harmless wash sweeping forward at 5 u/s against a 2 u/s current - it will catch a dawdling player and it cannot kill them. This is the surge VERB in its safest possible form, 1200 units before L2's teaching burp and 2500 before L2's lethal finale. By the time an acid wall is genuinely chasing them, the player has met the shape of it twice." },
    { "s": 540, "type": "checkpoint", "name": "Oropharynx" },
    { "s": 560, "type": "pickup", "kind": "biopsy_sample", "count": 1, "theta": 2.36, "rho": 0.9, "note": "SAMPLE 3/3 - a tonsillar crypt, where C put it. In the funnel, where the current has started to build: the last sample is the first one that must be taken at speed, which is the shape of every sample from L2 onward." },
    { "s": 600, "type": "spawn", "enemy": "amylase_droplet", "count": 2, "spread": 40, "note": "Traffic in the funnel - the first time the player meets a known enemy while the flow is doing something to them." },
    { "s": 640, "type": "pickup", "kind": "mucin_glob", "count": 1, "note": "Last top-up before the exam. If the mast cell went badly, this is the difference." },

    { "s": 700, "type": "gate", "id": "epiglottis", "to": "L2_esophagus", "note": "The exam: dive through on the swallow. Timing gate, not a boss." }
  ]
}