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Reactor and pod-tow rules

Pro packv3.0.0-12DArcade

Two objectives for a cave-flying game, a reactor to sabotage and a pod to rescue, each a rule you can take on its own, and a preset in the style of Thrust that puts them together with six planets traced from the original.

This is a Pro pack. Upgrade to Phaser Pro to use it in your games.See Phaser Pro →

Released October 19, 2026 · updated October 20, 2026

Reactor and pod-tow rules: a screenshot of its demo
A note about these graphics

Expansion packs don't come with graphics. This screenshot is one way of drawing what the pack does, made for its demo: none of the sprites, tiles or backgrounds in it are in the pack.

That's by design. A pack is a game's logic, mechanics and effects, and it works with whatever art you give it. Some packs draw effects, backdrops or 3D scenes of their own, but none carries a game's sprites.

So the look is yours. Make the art on phaser.io, bring your own, or let your agent draw it in code: the same pack can look like anything.

The pack

thrustRules

function thrustRules(): Pack<{ thrustRules: typeof api }>

Install the thrust-rules API (game.thrustRules): its rules for cave-flyer and its preset.

Helpers

POD

const POD: "pod"

The pod's id in the thrust-craft world.

podOf

function podOf(state: CaveState): PodState | undefined

The pod's state in a session, or undefined without podRule.

podRule

function podRule(o: PodOptions = {}): CaveRule

Thrust's pod: the objective is to tow it out through the orbit line. The ship needs a beam with a pod setting. While towing, the view follows the middle of the ship and the pod, and the beam cannot take cells.

reactorCritical

const reactorCritical = (state: CaveState): boolean=> …

The reactor is critical: counting down, or blown.

reactorOf

function reactorOf(state: CaveState): ReactorState | undefined

The reactor's state in a session, or undefined without reactorRule.

reactorRule

function reactorRule(o: ReactorOptions): CaveRule

Thrust's reactor. Bases marked gated hold fire while it is stunned or counting down. A crash while it is critical ends the planet as destroyed (no bonus, the next mission's guns punished by gunLevel.destroyed).

THRUST_GRAVITY

const THRUST_GRAVITY: number[]

Gravity per planet in pixels/s^2: the ROM's gravity_FRAC (5, 7, 9, 11, 12, 13)/256 y units per active tick.

THRUST_SHIP_OUTLINE

const THRUST_SHIP_OUTLINE: Vec2[]

Thrust's ship, drawn upright (nose up): an arrowhead with a notched tail.

thrustGunCone

function thrustGunCone(param: number): { dir: number; spread: number }

A gun's fire cone from its gun_param: angle index = base + rnd(0..spread mask) + rnd(0..3), 0 up, clockwise.

thrustPlanets

function thrustPlanets(): CavePlanetDef[]

Thrust's planets as cave-flyer planets.

thrustPreset

function thrustPreset(o: ThrustPresetOptions = {}): CaveFlyerDef

Thrust (1986). Easy and Normal change only the guns' fire rate (x0.4, x0.7), the starting fuel (2000, 1500) and the spare ships (5, 4); Arcade is the ROM: 1000 fuel, three spare ships, an extra ship every 10,000.

Types

PodOptions

interface PodOptions

The pod rule's options.

  • bonus?: { per: number; offset: number; destroyed: number } — The mission bonus for towing it out: per x (planet index + offset), plus destroyed if the reactor is critical.

PodState

interface PodState

The pod's state.

  • pod: "stand" | "towed" | "lost" | "none" — On its stand, towed, lost with the ship, or none on this planet.
  • deathPod: boolean — It was on the rod when the ship died.

ReactorOptions

interface ReactorOptions

The reactor's numbers (the original's units: damage bytes, seconds converted from its ticks).

  • damage: number — Damage at the start of each planet.
  • hitRandom: number — Random damage added per hit: 0 to this.
  • critical: number — Damage over this starts the countdown.
  • stunPerDamage: number — The guns stay quiet for the new damage times this many seconds.
  • startStun: number — Stun at the start of a planet and after a respawn, seconds.
  • countdown: number — Counts in the countdown.
  • countdownStep: number — Seconds per count.

ReactorState

interface ReactorState

The reactor's state.

  • damage: number — Accumulated damage.
  • stun: number — Seconds the guns stay quiet.
  • countdown: number — Countdown count, -1 when not critical.
  • countT: number — Seconds to the next count.
  • alive: boolean — Still standing.
  • present: boolean — This planet has a reactor.

ThrustPresetOptions

interface ThrustPresetOptions

Options for thrustPreset.

  • difficulty?: CaveDifficulty — Easy, Normal or Arcade (the ROM's tables). Default 'arcade'.
  • seed?: number — Seed for gun aim and reactor damage.
  • guns?: number — Multiply the guns' fire rate. Default from the difficulty.
  • gravity?: number — Multiply every planet's gravity. Default 1.
  • lives?: number — Spare ships at the start. Default from the difficulty (3 in the arcade).
  • fuel?: number — Starting fuel. Default from the difficulty (1000).
  • podMass?: number — Pod mass relative to the ship. Default 1 (the ROM's midpoint physics: thrust halves when towing).
  • tether?: "rod" | "rope" — Tow on a rigid rod (the original) or a rope.
  • planets?: number[] — Which planets, by index 0-5, in play order. Default all six.