# Pulsepath GDD v0.1

## Product promise

Drag the route. Read the beat. Release the pulse. Route a signal through phase gates that only open on
their matching arrival beat.

## Core rules

1. The board is a deterministic orthogonal grid with a source, receiver, open cells, walls, and phase gates.
2. A route is a non-repeating chain of adjacent open cells beginning at the source.
3. Each new cell advances the visible beat by one.
4. Cyan gates accept even arrival beats; amber gates accept odd arrival beats.
5. Releasing resolves the route in order. A gate mismatch fails at that gate and leaves the route editable.
6. Reaching the receiver with every gate accepted wins the board.

## Content

The prototype contains 50 reachable boards from four deterministic templates. The production target
is 120 boards across six gate and obstacle families, with no procedural difficulty claims until a
solver verifies each board.

## UX and safety

Mobile-first portrait, one-thumb drag, no document scroll, high-contrast gate colors plus parity
labels, mouse/click and keyboard fallbacks for web/desktop, reduced-motion-safe CSS, and a
replayable FTUE. No ads, accounts, or network are required by the core loop.