Coastal Cruise

Ride three hand-built seaside routes on a mint scooter, hopping crates and crabs to deliver every parcel.

Three.js4 build stagesComplete game available

Make it yours ↓Play full game ↗

Local build pack · No model call starts on this page

THE GAME LOOP

A small idea worth finishing.

Three lanes with timed slides and a hop; tall barriers must be steered round, crates, potholes and crabs can be hopped
Bumps cost a parcel, slow you and give brief immunity; a third bump in one stretch returns you to the last checkpoint
Optional mailbox lanes trade a parcel for medal progress; balloon parcels need a hop; scooter upgrades between routes

THE LOOK & FEEL

A world with its own personality.

Original seagull in a courier cap on a rounded mint scooter whose basket shows the parcels you carry
A gently winding road through layered scenery: quay town with boats, faceted cliffs with shrubs, sunset dunes
Clouds, distant headlands and stage props add depth while the lanes ahead stay readable on a phone

MADE FOR THUMBS

Plan the phone experience first.

Lane buttons bottom-left, a big Hop button bottom-right, plus swipes on the road; all 48px+ in safe areas, with the road ahead kept clear of HUD and thumbs.

The playbook requests H5 layouts and input. Real-device playtesting is still part of the build.

01 / MAKE IT YOURS

Same spark. Your world.

Change a few details. The brief and every build stage update together.

Your main characterYour worldWhat the player wants to achieveA personal touch Optional

02 / YOUR BUILD PLAYBOOKThree.js direction

Create an original seaside delivery runner as one self-contained browser game in Three.js (WebGL2). The player is a seagull courier on a mint scooter riding through a harbor quay, a windy cliff road and dunes out to a lighthouse. Goal: reach each route's finish on time with the parcel quota.

The scooter rides forward on its own; the player slides between three lanes and hops. Routes are hand-authored rows: parcels, high parcels that need a hop, tall barriers to steer round, crates, potholes and crabs that can be hopped, and optional mailbox lanes that deliver a parcel. Every row must leave a reachable lane, with spacing that leaves time to react. A bump drops a parcel, slows you and grants brief immunity; a third bump in one stretch returns you to the last checkpoint with the parcels you had there.

Three routes with distinct scenery and obstacle patterns, three checkpoints each, a quota and a deadline. Medals reward deliveries, a clean run and par time. Pick a scooter upgrade between routes; allow route replay. Add a practice lane, two paces, pause with settings and a result screen.

The full pack adds the H5 controls, build contract and acceptance checks.

Copying, downloading and customizing are free. No build starts here.

Read the full local build pack

# Coastal Cruise — SiGameGen original game brief

Prompt template, not a prebuilt game. Engine direction: Three.js.

## Project brief

Create an original seaside delivery runner as one self-contained browser game in Three.js (WebGL2). The player is a seagull courier on a mint scooter riding through a harbor quay, a windy cliff road and dunes out to a lighthouse. Goal: reach each route's finish on time with the parcel quota.

The scooter rides forward on its own; the player slides between three lanes and hops. Routes are hand-authored rows: parcels, high parcels that need a hop, tall barriers to steer round, crates, potholes and crabs that can be hopped, and optional mailbox lanes that deliver a parcel. Every row must leave a reachable lane, with spacing that leaves time to react. A bump drops a parcel, slows you and grants brief immunity; a third bump in one stretch returns you to the last checkpoint with the parcels you had there.

Three routes with distinct scenery and obstacle patterns, three checkpoints each, a quota and a deadline. Medals reward deliveries, a clean run and par time. Pick a scooter upgrade between routes; allow route replay. Add a practice lane, two paces, pause with settings and a result screen.

## Local build contract

Work in a new isolated project directory through my signed-in local Claude Code subscription. Do not call a separate model/image API, change provider settings, use an API gateway or spend on a paid service. Do not deploy, publish, commit or push without an explicit follow-up instruction. Read applicable repository instructions first.
Build a complete browser game with the full campaign and progression in the project brief. Keep the rules-first stage as development work, then finish the art, game feel and release review before calling the game complete. Include an interactive skippable tutorial, distinct data-driven levels or missions, meaningful progression, fair failure and chapter retry, a final ending, settings and replay. Pin locally installed dependencies; bundle code, engine, fonts and assets into a self-contained HTML. Use original procedural art or supplied assets with permission and keep a licence inventory. Separate deterministic rules, input, renderer, UI, audio and scene data.
SiGameGen embed contract: opaque-origin iframe, no runtime CDN/imports, fetch/XHR/WebSocket, browser storage, popups or page navigation. Keyboard and touch must work without pointer lock on phones. Emit only integer points: parent.postMessage({type:'sigamegen:game-event',version:1,event:'started',score:0}, '*') once per run, and the same schema with event:'game_over' and the final score once at win/loss. Points are not money.
Save campaign checkpoints through the host only. Request {type:'sigamegen:save-request',version:1,gameId:'<game-id>'}; accept {type:'sigamegen:save-state',version:1,gameId,state,storage:'available'|'unavailable'} only from window.parent. Validate your actual save schema, own-key IDs and ranges. Post {type:'sigamegen:save',version:1,gameId,state} with a small plain JSON state (<=8192 UTF-8 bytes); state:null explicitly clears it. Show saved only after {type:'sigamegen:save-status',version:1,gameId,status:'saved'|'cleared'|'unavailable'|'invalid'} from the parent. Failed or missing acknowledgements must stay honest and allow retry; missing storage must not block play. Local progress and scores never authorize money or rewards.
Audio is off until opt-in. Support volume, reduced motion, safe areas, controls at least 48px, portrait/landscape camera fit, pointercancel, pause/restart confirmation, tab hide and return without fast-forward. Tutorial hints must leave the action visible, and primary actions must fit short landscape screens. Stop rendering while paused, hidden and on results; cap particles/enemies and mobile DPR at 1.5. Target <=1.6MB raw / 400KB gzip; measure the actual result, not a promise. Test actual game fairness, legal-input progression, loss/retry and save validation; then review the full campaign, upgrades, ending and replay in the real sandbox at 320x568, 393x852, 852x393 and desktop. Keep inspection bots and debug controls out of release builds. Report passed checks and untested device/audio paths separately.

## Continue in the same Claude Code project

### 1. Core mechanics

Build deterministic fixed-step rules first with greybox shapes for a seagull courier on a mint scooter through a harbor quay, a windy cliff road and dunes out to a lighthouse: route rows, lane slides, hops, low and tall obstacles, crabs, parcels, mailboxes, bumps with immunity, checkpoints and wipeouts, quota, deadline, medals and upgrades, so a player can reach each route's finish on time with the parcel quota. Write a route solver and test that no row is fully blocked and every safe lane has a path onward, the quota is reachable even with every delivery, and an input-only bot medals every route while idle or careless riding loses.

### 2. Art pass

Art pass: model a seagull courier on a mint scooter from primitives with a cap, satchel and a basket that shows carried parcels; animate lean, hop and bump wobble. Build a harbor quay, a windy cliff road and dunes out to a lighthouse along a winding road with layered depth: houses, boats and bunting; faceted strata cliffs with shrubs and a rail above the sea; dunes, fences and umbrellas; clouds and distant headlands. Theme each obstacle per route and add checkpoint gates and a destination. Keep a licence note.

### 3. Game feel

Make the road toward reach each route's finish on time with the parcel quota readable at speed: a camera that frames the rider low and shows the lanes far ahead (higher in portrait), parcel sparkles, bump shake that reduced motion turns off, a wipeout fade and checkpoint toasts. Show parcels against the quota, deliveries, bumps left and route progress with checkpoint marks. Add opt-in calypso music and effects with volume sliders, and a practice lane whose drills need a real lane change, a real hop and a real dodge.

### 4. Review & ship

Review a seagull courier on a mint scooter in a harbor quay, a windy cliff road and dunes out to a lighthouse as a release candidate at 320x568, 393x852, 852x393, 852x345 and desktop: controls 48px+, the rider and the road 25 to 45 metres ahead clear of controls and HUD, every menu reachable. Clear inputs and swipes on blur, pointercancel, pause and hide. Validate saves with own-key ids, show 'saved' only after the host confirms, and ship one offline HTML without dev tools and with one started and one game_over per run.

## Acceptance checks

- A solver proves every route row leaves a reachable lane from any safe position and the quota is reachable with all deliveries.
- An input-only bot earns a medal on every route at both paces, while idle riding and late, hop-less riding lose.
- Bumps during immunity cost nothing; a third bump in a stretch restores the checkpoint's parcels and re-arms that stretch.
- Practice drills only pass on a real hop over the crate and a real lane change round the barrier in your lane.

## Research references

These are design references, not included code or assets. The prompts are original SiGameGen briefs. Model attribution in external repositories is creator-reported.

- Pelican Bike · riba2534: https://github.com/riba2534/claude-opus-5-5-demo
  Creator reports a Claude Code session producing procedural coastal riding, character motion and inline HTML. Our original full game uses a seagull courier, mint scooter, three routes, upgrades and medals. Its cover is a capture from the normal gameplay camera.

Want a quick 2D sketch first?

The online builder adapts these mechanics to Canvas 2D. The full Three.js version is built in your local Claude Code project.

Open a 2D sketch ↗Opening the builder is free. Only confirming Build game uses platform credits.

DONE MEANS PLAYABLE

The checks this game should pass.

A solver proves every route row leaves a reachable lane from any safe position and the quota is reachable with all deliveries.
An input-only bot earns a medal on every route at both paces, while idle riding and late, hop-less riding lose.
Bumps during immunity cost nothing; a third bump in a stretch restores the checkpoint's parcels and re-arms that stretch.
Practice drills only pass on a real hop over the crate and a real lane change round the barrier in your lane.

These are requirements for your future build, not results already verified for this prompt.

RESEARCH, WITH CREDIT

What shaped this playbook.

Original SiGameGen prompts authored in our local Claude Code subscription session. References inform the design; their code, assets and prompts are not bundled. External model attribution is creator-reported.

GitHub

Pelican Bike · riba2534 ↗

Creator reports a Claude Code session producing procedural coastal riding, character motion and inline HTML. Our original full game uses a seagull courier, mint scooter, three routes, upgrades and medals. Its cover is a capture from the normal gameplay camera.