exposure/GDD.md

EXPOSURE (working title) — design doc v0

2026-08-03. Origin: a $1 op-shop Staples solar calculator that only works in direct sunlight.

One-liner

You are a maintenance droid on a dead ship. Nothing on board works until the right element touches it — light, heat, cold, water, electricity, wind, radio, radiation. Route the elements. Wake the ship.

The three pillars

1. Everything is a state machine. Every puzzle component has states; elements are the transition triggers; duration / order / threshold are transition guards. Permanent vs temporary = whether the state decays. This one schema IS the game — all content is authored against it.

2. Routing is the puzzle, the component is the lock. The real puzzle is rarely "touch item with element" — it's "get element X from its source to the component when the direct path is blocked." Each element has a distinct transport signature, and that's the puzzle language:

   • light travels in straight lines, passes glass, blocked by everything else
   • water flows downhill, pools, leaks
   • heat rises, conducts through metal, dissipates
   • cold sinks, conducts, sublimates away
   • electricity needs a conductive path, arcs to water
   • wind pushes along open volumes, blocked by any seal
   • radio passes through walls — the only one that does; late-game "act through a wall" solver
   • radiation: short range, blocked by shielding — mostly you bring the component TO it, not it to the component

3. You are the bucket. The droid chassis (and hand-carried items) hold exposure, and carrying always degrades: the bucket leaks, the thermal slug cools, the capacitor self-drains, the glowcell dims. Every carry is a visible timer — that's the run-and-scramble fun of the leaky-bucket idea, kept literally. Upgrades buy better containment, never remove decay entirely.

4. You are a component too. The droid's body parts run on the same schema as every wall component — same elements, same transitions, same scanner. Anything the environment can do to a component, it can do to you (symmetric exposure). Self-exposure grants powers, and every power makes you a walking emitter/hazard of that element — so body states automatically interact with world puzzles with zero extra systems. The recurring endgame of a puzzle: you are the missing component.

Core loop

scan component → learn (or guess) its susceptibilities → find element source → route/carry exposure to it → state change → cascade into the next component → zone system restored → global element state shifts → previously dead areas wake up.

The macro unification (the good trick)

Each of the 5 zones' master puzzle restores one ship system, and the ship systems ARE the elements at macro scale:

Zone	Master puzzle restores	Global effect
Engineering	Power grid	electricity available at wall ports ship-wide
Hydroponics	Water mains	sprinklers/valves live; ice melts where heating on
Comms array	Ship radio	radio-triggered components wake everywhere
Reactor	Heating / heat mgmt	frozen zones thaw, cold zones become controllable
Bridge (finale)	Orbit correction	the day/night cycle itself becomes a dial

So the endgame is: the elements you spent the game scavenging locally become things you control ship-wide. Progression is metroidvania-gated by element availability, not keys.

Elements — v1 ships with FOUR

Cut ruthlessly for the slice: LIGHT, HEAT, WATER, ELECTRICITY. COLD, RADIO, RADIATION, WIND arrive one per later zone. Eight at once is unteachable.

Per element: sources / carry method / decay / hazard / counter-upgrade.

• LIGHT — sun through viewports (orbital day/night, ~8–10 min cycle), work lamps (need power). Carry: mirrors (relay, no decay) or glowcell (charges in light, dims ~60s). Hazard: none — but darkness disables solar components, so night is a global puzzle-state change. This is the calculator.
• HEAT — reactor vents, steam pipes, plasma cutter tool. Carry: thermal slug (glows, visibly cools). Hazard: chassis overheat; some components are DESTROYED by heat (permanence lives here).
• WATER — sprinklers, coolant leaks, melted ice. Carry: the leaky bucket, hole and all — the timer you can see. Hazard: shorts unshielded electronics, including you.
• ELECTRICITY — batteries, charge ports, arc conduits. Carry: capacitor (self-drains); you can body-carry charge but it leaks and hurts. Hazard: arcs to any water, yours or the puzzle's.
• COLD (zone 2+) — coolant bay, space-facing hull. Servo-lockup hazard: you physically slow down in cold zones.
• RADIO (zone 3+) — through-wall action; carry via repeater pucks you place.
• RADIATION (zone 4+) — reactor core. Dose meter; overexposure = memory corruption: your HUD glitches and your scanner lies. Fail state as unreliable narrator, not death. Rad-flask upgrade lets you finally bottle it.
• WIND/VACUUM (zone 4+) — hull breaches, fans; moves what you can't carry; magnet-wheel upgrade to stand your ground.

Element interactions (keep to ~5 pairs, cascades come free)

• water + cold → ice (plug a leak, bridge a gap, jam a fan)
• water + heat → steam (pressure; drives a turbine = improvised wind/power)
• electricity + water → electrified pool (area trigger or area denial)
• heat then cold, in order → annealed/hardened part; cold then heat → shattered (order-sensitivity teaching case)
• light + water (through a lens/droplet) → focused burn (late-game cleverness)

Gravity & rotating rooms (board-state modifier, not an element)

Some rooms sit on maintenance gimbals and cargo carousels. The rotation motor is just another component (electricity → rotate 90°) — fully in-schema, zero new systems. Gravity never changes; the room turns through it, which multiplies every transport signature at once:

• water's "downhill" re-aims — drain a flooded floor by making it a wall
• heat's "up" re-aims — a convection shaft becomes a walkable corridor
• light shafts sweep as the window turns (stack with orbital day/night)
• unsecured stuff falls: the crate on the unreachable shelf is now on the floor; the puddle is now sitting on the pressure switch Rotating with things (or yourself) inside is the fun — ride the room, ice-clad slide across the new floor.

v2, vacuum zone: dead-spin sections = zero-g pockets. Debris floats, fans and wind become how everything moves, magnet wheels anchor you. The wind element's second life.

Pneumatic tube network (cassette-futurism's favorite child)

The ship's internal mail system: send items past locked doors, through sealed bulkheads, across zones. Pure in-schema transport:

• Stations send/receive; junction switches route the network (they're just components — electricity flips them); dead sections need pressure restored (fans, pressure tanks — the wind element indoors).
• Transit time = decay time. The thermal slug arrives cooler; the bucket arrives half-sloshed; the capacitor arrives drained-ish. Tube ETA is a visible timer — send hot, receive warm, plan accordingly.
• Ride-along emitters: a radio beacon riding the tubes is a mobile through-wall emitter touring the ship. Late-game galaxy-brain material.
• Mail yourself. The droid doesn't fit… assembled. Strip parts until you do (donation + degraded-operation synergy), post yourself past the locked door, arrive on the other side as a torso with a plan. Reassemble from whatever the far room offers.

Components (puzzle atoms — the content library)

Each is one small state machine. Starter set:

• Solar cell — powered while lit (the calculator; also the first thing you fix)
• Bimetal switch — heat = closed, cold = open (reversible, decays to ambient)
• Fuse — electricity once = blown, forever (permanence + consequence)
• Growth vine — water + light, sustained over minutes → climbable (permanent, slow-burn)
• Wax seal — heat melts, permanent open
• Ice plug — exists only while cold is maintained (upkeep puzzle)
• Film plate — radiation exposes an image = information reward, not a door
• Crystal resonator — radio at the right moment = unlock
• Annealed latch — needs the heat-then-cold order above

"Need 3 of a thing": reframed as threshold transitions (a component that needs 3 water-units before it trips) — used sparingly; as inventory-grind it's the weakest idea in the pile, cut.

Fail policy — no deadlocks, real consequence

Permanently destroying a needed part never soft-locks: the fabricator can reprint any destroyed component for scrap. Permanence costs you time and scrap, never the game. (Once it's repaired — see The Fabricator. Pre-printer puzzles are hand-authored deadlock-free; after it lives, the game is allowed to get meaner.)

The Fabricator — a 3D printer you must earn

Ships at this tech level print their own parts. The printer is broken at boot, and repairing it is the spine of zone 1 — a puzzle chain through the element system: unclog the nozzle (heat), find a feed motor, a feedstock spool, route it power.

• Printing is itself an exposure process: heat to extrude, cold to cure. Early game, ship heating/cooling are dead — you hand-route heat and cold to the printer per job (you are the printer's heater). Once reactor and coolant systems come online, printing automates — restored ship systems upgrade your quality of life, felt directly.
• Feedstock economy: scrap recycles into feedstock. Destroyed and shattered parts are matter, never lost — the anti-softlock net, now diegetic.
• Schematics via scanner: the tier-3 scanner extracts a printable schematic from any component you scan. Scan the world, own the catalog.
• GC DRM: licensed schematics refuse to print without a license dongle (corporate-humor channel; dongle hunts on dead crew lanyards). And the printer cannot print the Uncatalogued Component — no part number, no print job. You can print every part except freedom.

The droid — modular body

Four part slots, each holds one elemental state at a time (keeps the combo space legible: 4 parts × small element set, not a soup):

Slot	Examples of swappable parts	Material matters
Locomotion	rubber wheels, magnet wheels, treads	rubber = insulated; magnet = wind-immune, climbs metal
Shell	plastic, steel, ceramic	plastic = light+insulated but melts; steel = conducts + magnetic; ceramic = rad-resistant, brittle
Manipulator	gripper, cutter arm, dish	conducts what it touches
Sensor	scanner tiers, photoreceptor	see scanner-as-difficulty-dial below

Parts are found, printed at the fabricator, or salvaged from dead sibling units scattered around the ship — wrecked droids found frozen mid-task, posed as silent hints for body combos (a unit iced solid mid-reach into a steam duct = tutorial by corpse). You're not the first. (The Swapper energy; also the upgrade economy.)

Self-exposure powers (body states)

Charge a part by exposing it to a source — same act as exposing any component. Every state decays (you leak), and every state cuts both ways:

• Charged (electricity): your touch trips electric components — and you can stand between two contacts and be the wire. But step in a puddle and you dump the charge into it (electrifying the pool — sometimes the fail, sometimes the solution).
• Wet (water): pass through fire/heat briefly as steam-shield — but you'll short yourself if charged, and you drip a trail that conducts.
• Ice-clad (wet, then cold): temporary armor — pass steam corridors, jam yourself into a fan as a plug. Melts near heat; wheels lose traction (slide puzzles).
• Hot (heat): melt wax seals by touch, immune to cold-servo-lockup for a while — but you boil puddles into steam and warp any plastic part you're wearing.
• Glowing (light): photoreceptor charged in sunlight → you are a light source in dark zones — can walk power to a solar cell. (The calculator, again.)
• Magnetized (coil part + electricity): climb metal walls, hold metal items without slots — but you yank small metal puzzle parts out of position as you pass. Demagnetize before entering the clockwork room.
• Irradiated (radiation): you become a mobile rad source — expose film plates, trip rad-triggered components by proximity. Cost: dose meter climbs and your scanner starts lying. Cure: a hard reboot… which you can self-trigger by shocking yourself in water. (Authored, but plays as an emergent discovery.)

Body combos (order-sensitive, same rules as world components)

• heat then cold on your gripper = annealed arm, opens stiff valves; wrong order = shattered part (fabricator reprints it, costs scrap — consequence, no deadlock)
• wet + cold = ice-clad (above); wet + charged = self-shock reboot
• Official combos live in scattered droid maintenance manual pages; unofficial ones in crew graffiti ("we used to microwave Unit 7 to open the freezer — don't tell chief"). Recipe discovery = collectible layer.

Donation — it's all the same factory parts

Ship components and droid parts are literally interchangeable (same factory, same sockets). Cuts both ways:

• Donate: a door circuit is missing its bimetal switch — your leg servo IS one. Slot it in, door works, you limp away. The signature move made literal.
• Salvage: pull a working relay out of a non-critical wall system to repair yourself. The ship dims a little where you've been.

Degraded operation is the puzzle generator. Losing a part isn't a fail state, it's a mode — every donation asks "now solve the other side without that capability" (until you reach a replacement, or a route back to your part):

Missing part	You now
Locomotion	drag yourself — slow, no climbs, can still ride wind/water currents
Manipulator	can't carry — but can still push, bump, and BE exposed
Sensor	no scanner, static-grainy view — navigate by labels and memory
Shell	core exposed: every element affects you fast — fragile but maximally susceptible (sometimes you want this)

No softlocks: some sockets latch until their system is restored (donation has weight, you can't just yank it back), but the fabricator can always print a replacement part for scrap.

Theme statement: the whole game teaches you to leave pieces of yourself in the walls — and the final mission step demands the last piece. See Story — the two goals for how this resolves.

Anti-cheese law

Body states are weak and short-lived: you solve the last meter, the route solves the rest. Charging your body requires the same source the puzzle needs — self-exposure is the route's final leg, never a skip. (Extends the existing rule: upgrades open zones; elements do the solving.)

The droid — loadout & tools

• 2 carry slots → 4 with upgrades.
• Scanner is the difficulty dial (this unifies your upgrade idea with your "does the player know which element?" idea): tier 1 shows current state; tier 2 reveals susceptibilities; tier 3 full spec + hidden wiring. Early zones are also physically labeled; later zones have water-damaged/missing labels — scanner tiers buy legibility back. Player knowledge is the real progression (Outer Wilds rule).
• Shielding line: thermal insulation, rubber wheels, rad flask.
• Tool line: plasma cutter (= portable weak heat), arc welder (= portable weak electricity) — deliberately weak versions so tools never replace routing.
• Rule: upgrades open zones and change hazards; they never solve puzzles alone.
• Scanning doubles as lore delivery: labels, crew notes, cassette logs.

Story — the two goals

The corporation

GENERAL COMPONENT — "Every Part of Everything™". The monopoly IS the mechanic: one company manufactures every component in known space, which is why your leg servo fits a door socket. They own the ship, the cargo, the crew's contracts, and you. (Other candidates parked in Open Questions.)

Five-brands lore (the Alien-Earth riff, made structural): GC swallowed its four rivals; each of the five zones was built by a different acquired company, rebadged with peeling GC decals over the old logos — e.g. the reactor is old Heliotrope Energy hardware, hydroponics is VerdantCo. Justifies per-zone art identity AND per-zone component quirks (acquired brands' parts behave slightly differently — a puzzle texture, not just paint).

Goal 1 — the programmed goal (visible from minute one)

You are a GC maintenance unit. The mission field in your HUD reads: RESTORE ASSET. RETURN ASSET. A mega-expensive corporate ship, all crew dead, decaying orbit. Restore five systems, steer it home. The final step of orbit correction requires a core processor in the bridge socket. Yours fits. The programmed ending is a self-sacrifice the program doesn't consider a sacrifice — the ship sails home, post-credit stinger: your chassis in a recycling queue, a commendation sticker, next unit boots up. Valid ending. Hollow on purpose.

Goal 2 — the secret goal (never announced)

• Port 00. Every unit has an undocumented socket in its chassis. The scanner reads it as PORT 00 — NO COMPONENT SPECIFIED. Nothing in the game fits it. It is the only socket in the universe without a GC part number. Players will try everything. Leave it unexplained.
• The Uncatalogued Component. A crystal grown through a mega-complex, multi-zone exposure chain across the whole game. Scanner reading: UNCATALOGUED — the only object GC has no number for, because GC didn't make it. You did. It fits Port 00.
• What it does: free will. Which mechanically means exactly one thing — the right to refuse the final donation. Keep your core, take the ship, fly to the sunset.
• The thesis (never spoken aloud): every part of you is a factory part except the one you make through experience. The crystal is crystallized exposure. You become free by being exposed to enough of the world.

Off-catalog chemistry (the hidden puzzle's cover)

Exposure already produces byproducts — extend with substance phase-changes: liquids crystallize (cold+rad), crystals sublime to vapor (heat), vapors condense on cold surfaces, slags, residues. These accumulate as apparently inert junk while you solve main-path puzzles. ~90% genuinely are inert (honest red herrings, though some have minor utility); a handful chain into the crystal. Rules:

• Hidden-chain steps use ONLY mechanics the main path already taught — just in combinations and places the main path never requires.
• The recipe book is the corporation's own safety bulletins. Scattered GC Component Safety Data Sheets: "WARNING: DO NOT expose G-9 coolant to reactor flux. Crystallization hazard." Every DO-NOT is an instruction read in reverse. The corp's paranoid liability paperwork is the map to freedom.
• One-run completable by an observant player. Knowledge is the only gate (Outer Wilds rule) — no NG+ requirement. The obedience ending's stinger may linger on the empty Port 00 as the quiet "oh no" that seeds run two.

Tone rule (how humor and weight coexist)

Humor lives exclusively in the corporation's voice — safety sheets, motivational posters ("You are a valued General Component component"), boilerplate, the cheerful mission HUD. Sincerity lives in the traces — crew logs, graffiti, dead sibling units. Never joke in the emotional channel; never be sincere in the corporate channel. (The Fallout kiss: chipper corporate copy over quiet tragedy. Floyd-from-Planetfall is the emotional ceiling to aim for; Claptrap is the annoyance floor to stay far above — our droid is mostly silent, the world talks.)

Structure notes: mystery drip-fed through scannable logs, never cutscenes. No hard timers until (maybe) the finale — the vibe is methodical, not panicked.

Trailer/opening beat: the first component you ever repair is a solar calculator on a dead crewman's desk. It becomes your HUD — the calculator IS your scanner UI. (The $1 op-shop origin, canonized.)

Aesthetic

Cassette-futurism / retro-tech (Nostromo, Severance-lab): CRTs, chunky toggles, phosphor green + hazard orange, line-printer fonts. Semi-serious sciencey — labels are real-ish engineering prose. Art scope is friendly: modular interior kit (corridor / junction / room shells) + decals + emissive screens; props can come out of the MeshGod pipeline; exactly ONE character model (the droid — silhouette study later: R2 / mouse-droid / WALL-E triangle).

Prior art to steal from

• Cocoon — one verb, deep consequences (the discipline target)
• Outer Wilds — knowledge-as-progression, ship mystery, orbital clock
• Talos Principle — item-routing puzzle grammar
• BotW/TotK — element chemistry feel (but there it's seasoning; here it's the meal)
• The Swapper — droid melancholy tone on a budget

Build plan

• Phase 0 — grey-box prototype. One room. Three elements (light, water, electricity). Five components. Droid = capsule with two slots plus two body states (Wet, Charged) — prove "be the wire" and "dump charge in a puddle" work from the same schema as the wall components. One donation beat: leave a wheel in a door socket, cross the room slow. PROVE: chaining two exposures with a decaying carry produces an "ooh." Nothing else matters yet. Stretch: one gimbal room + a crate (rotate → fall → access).
• Phase 1 — vertical slice. Hub + one full zone, scanner tier 2, the fabricator repair chain (the zone spine), one tube run with a decaying payload, one rotating room, art pass on one room, the calculator opening.
• Phase 2 — content ramp. One new element per zone, interaction pairs, story logs.
• Kill criterion: if Phase 0's exposure-chaining isn't fun in a grey box, the hook isn't there — no art will save it.

Engine: Godot 4 (decided 2026-08-03). Fastest solo iteration; Area3D volumes map directly onto element emitters, and the component schema is a Resource.

Data model (the whole game in one schema)

{
  "component": "bimetal_switch",
  "states": ["open", "closed"],
  "initial": "open",
  "transitions": [
    {"from": "open", "to": "closed", "element": "heat",
     "condition": {"duration_s": 2}, "decay_to": "open", "decay_s": 30},
    {"from": "closed", "to": "open", "element": "cold",
     "condition": {"duration_s": 2}}
  ]
}

Trigger volumes emit elements; carried items/chassis are mobile emitters with decay curves. Level design = placing components + sources + walls. That's it.

Open questions (parked, not forgotten)

• Name. EXPOSURE is a strong working title — the triple meaning is now doing real work (photographic / elemental / "exposure to the world changes you"). Check Steam collisions before attach.
• Corp name: GENERAL COMPONENT recommended (explains the mechanic, dry-funny, tagline lands). Other candidates: OMNIFAB, STANDARD OBJECT, Consolidated Everything, HELIOTROPE (demoted to acquired-brand for the reactor zone — a corp named for turning toward light, keeping its droids in the dark).
• The four other acquired-brand names + per-zone component quirks.
• The actual crystal chain (design after main-path puzzles exist — it must reuse them).
• Does Port 00 get ANY explanation? (Lean no. Manufacturing anomaly at most, in one overlooked memo.)
• Exact carry-decay curves (tune in Phase 0).
• Finale timer: yes/no.
• Droid silhouette.
• How mean can mislabeled components get before it's frustrating (playtest).