Tiderunner

A short pixel-art dash-platformer built with Loombridge. One screen, roughly 20 to 30 seconds to clear: run, jump, air-dash, collect every fruit.

This repository is a worked example. The game is the artifact; the point is how it was made. An AI agent built it end to end through Loombridge's MCP tools, working from a design brief and a machine-checkable acceptance contract rather than from a human copying files around.

TideRunner_02_Gameplay.mp4

The game

Genre	2D platformer, single-screen vertical slice
Objective	Collect all fruit. Reaching the flag is a secondary win trigger.
Engine	Unity 6000.3.20f1
Framing	16:9, static camera, pixel-perfect
HUD	Fruit counter (top-left), run timer (top-center), heart row (top-right)

Controls

Action	Keys
Move	A / D or Left / Right
Jump	Space, W, or Up
Air dash	Left Shift, X, or K

The jump is variable-height with coyote time and a jump buffer; the dash is one per airtime and refills on landing.

Running it

1. Clone the repo and open the folder in Unity 6000.3.20f1. The Loombridge bridge package is vendored at Packages/tarballs/, so the project resolves without network access.
2. Let Unity compile and import.
3. Open Assets/Scenes/Tiderunner.unity and press Play.

How it was built

The build was driven by an agent through Loombridge, not written by hand. The pieces that made that possible are all in this repository:

• BUILD-BRIEF.md is the design doc handed to the agent: the visual mock, the mechanics, the asset table with per-sprite import settings, and the ground rules. It forbids copying from any reference project, so the run tests whether the brief plus the skills are sufficient on their own.
• .loombridge/ACCEPTANCE.json is the acceptance contract: the machine-checkable definition of done that loombridge verify grades against. GAME_SPEC.md is its human-readable mirror; FEEL_SPEC.json locks the movement numbers.
• .claude/ and .codex/ hold the Loombridge agent surface: the slash commands and the skills (unity-2d-game, platformer-level-design, game-polish-2d, parallax-2d, verify-2d-game, and others) that carry the actual construction knowledge.
• Assets/Scripts/ is the result: the player controller, camera, HUD, juice, audio, parallax, and interactables, each authored from a skill reference through MCP.

Feel is a locked contract rather than a matter of taste. FEEL_SPEC.json pins run speed to 7 u/s, jump apex to 2.2 u at 325 ms, dash distance to 2.8125 u over 0.15 s, coyote time and jump buffer to 100 ms each. loombridge verify --snapshot grades measured drift against those numbers.

Reproducing the loop

With the Loombridge CLI installed:

loombridge doctor    # health-check the bridge wiring
loombridge status    # where the project sits in the build loop
loombridge verify    # run the Tier-1 gates against the contract

verify needs the Unity editor open for its live gates; the offline gates run without it.

On verification status: no graded verdict is committed to this repository. .loombridge/STATE.md reports phase planned with no design target approved, because verify artifacts and run reports are generated output and are gitignored. Run verify yourself against a clone to produce a verdict; do not read the presence of this code as a passing grade.

Repository layout

Assets/              game code, art, audio, scenes, shaders
  Scripts/           player, camera, HUD, juice, interactables, audio, parallax
  Scenes/            Tiderunner.unity
.loombridge/         acceptance contract, feel spec, game spec, design target
.claude/ .codex/     Loombridge agent commands and skills
Packages/tarballs/   vendored Loombridge Unity bridge
BUILD-BRIEF.md       the design doc the agent built from

Licensing

Code and project configuration are MIT licensed; see LICENSE. Bundled art, audio, and fonts carry their own licenses, including CC0 sprites from Pixel Frog's "Pixel Adventure" and the Press Start 2P font under the SIL OFL. See ATTRIBUTION.md for the full breakdown.