Backseat Buddy

Coach an original learner through a quiet yard, a lively town and a winding coast to the lighthouse.

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.

Seven bounded driving intents; ambiguous questions ask for clarification
Reaction delay, braking distance, readable hazards and confidence with two difficulties
Three sequential courses, course medals, checkpoint retry and a sunset ending

THE LOOK & FEEL

A world with its own personality.

Original seafoam and cream car with separate steering and spinning wheels
A visible adult driver, glasses and contextual expressions, readable road signs
Coherent yard, town and coast scenery with chase and cabin cameras

MADE FOR THUMBS

Plan the phone experience first.

Seven labelled 48px instruction buttons below the road, a short English text field, chase/cabin cameras and a pause menu. Landscape and portrait must show the next hazard. Microphone and cloud speech are optional.

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 complete Three.js driving-coach browser game. The learner is an adult learner named Juno Vale in a seafoam hatchback. Courses are set in a training yard, a school-zone town and a lighthouse coast. Goal: complete three courses with safe stops, correct turns and a final parking bay. The player is the passenger coach, using accelerate, slow, brake, stop, left, right and straighten instructions. Implement deterministic reaction delay, motion, collisions and braking distance. Questions and conditional or ambiguous instructions must ask for clarification, never guess. Add a training yard, town with stop signs and pedestrians, and a coast with cyclist, tunnel and lighthouse bay. Provide a six-action tutorial, Easygoing and Road Test, three-star results, course retry, pause, settings, checkpoints and a final sunset ending. Use original procedural models with moving wheels, a visible adult driver and readable chase/cabin cameras. Text and large touch buttons must complete every course offline. Optional host speech uses an exact reviewed line dictionary and cannot change the local physics or make microphone access mandatory.

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

# Backseat Buddy — SiGameGen original game brief

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

## Project brief

Create an original complete Three.js driving-coach browser game. The learner is an adult learner named Juno Vale in a seafoam hatchback. Courses are set in a training yard, a school-zone town and a lighthouse coast. Goal: complete three courses with safe stops, correct turns and a final parking bay. The player is the passenger coach, using accelerate, slow, brake, stop, left, right and straighten instructions. Implement deterministic reaction delay, motion, collisions and braking distance. Questions and conditional or ambiguous instructions must ask for clarification, never guess. Add a training yard, town with stop signs and pedestrians, and a coast with cyclist, tunnel and lighthouse bay. Provide a six-action tutorial, Easygoing and Road Test, three-star results, course retry, pause, settings, checkpoints and a final sunset ending. Use original procedural models with moving wheels, a visible adult driver and readable chase/cabin cameras. Text and large touch buttons must complete every course offline. Optional host speech uses an exact reviewed line dictionary and cannot change the local physics or make microphone access mandatory.

## 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

Separate rules, commands, courses and renderer. Build an adult learner named Juno Vale in a seafoam hatchback in greybox a training yard, a school-zone town and a lighthouse coast. Implement bounded command parsing and clarification, fixed-step reaction/braking, ordered goals, confidence/strikes and the full progression to complete three courses with safe stops, correct turns and a final parking bay. Test careful-input wins, careless/idle failures, question clarification, retry and strict save validation.

### 2. Art pass

Model an adult learner named Juno Vale in a seafoam hatchback with a coherent car silhouette, steering and spinning wheels, driver glasses and contextual expressions. Build distinct road environments for a training yard, a school-zone town and a lighthouse coast, signs, bays, crossings, tunnel and lighthouse. Provide real model thumbnails with dimensions, collision/anchor checks and licence inventory.

### 3. Game feel

Add a six-action practice, readable feedback, two cameras, difficulty selection, opt-in sounds, reduced motion and settings. Fit 48px command buttons and an accessible Type/Say field below the road. A question must offer choices. Make speech optional: text and buttons must achieve complete three courses with safe stops, correct turns and a final parking bay without a key, microphone or network.

### 4. Review & ship

Complete all three courses and the sunset ending; distinguish bot progression from human difficulty tests. Review actual 320x383, 320x568, 393x667, 852x345 and desktop game stages. Bundle pinned dependencies, fonts and original art with no runtime network. Export standalone HTML and a portable source ZIP with lockfile, README, licence notices and checksums. Rebuild in a clean directory. Keep dev bot hooks out of release.

## Acceptance checks

- All courses and the ending are reachable with legal inputs; careless and idle play fail.
- Questions, stale voice replies and paused/ended lessons never execute unintended commands.
- Model dimensions, moving parts, collision fit, actual thumbnails and licences are checked.
- The portable source rebuilds byte-identically and the exported game works with offline text and buttons.

## 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.

- Three.js engine: https://github.com/mrdoob/three.js
  Engine reference only. Backseat Buddy is an original local Claude Code project with three courses, bounded coaching instructions, a sunset ending and portable exports. Its cover is an actual game capture. Local text and buttons are fully playable; cloud speech remains an optional internal pilot.

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.

All courses and the ending are reachable with legal inputs; careless and idle play fail.
Questions, stale voice replies and paused/ended lessons never execute unintended commands.
Model dimensions, moving parts, collision fit, actual thumbnails and licences are checked.
The portable source rebuilds byte-identically and the exported game works with offline text and buttons.

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

Three.js engine ↗

Engine reference only. Backseat Buddy is an original local Claude Code project with three courses, bounded coaching instructions, a sunset ending and portable exports. Its cover is an actual game capture. Local text and buttons are fully playable; cloud speech remains an optional internal pilot.