KidGameMaker

KidGameMaker is a contract-first, zero-code side-scrolling game maker aimed at a child-facing editor with a real 2D runtime underneath it.

The child never sees code, file structures, sprite slicing tools, import settings, node graphs, or build systems. They place visual stamps, press Play, and the engine handles the rest.

Architecture

Svelte UI → Tauri IPC → Rust backend → JSON files → Godot runner

Phase Completion Status

Phase	Goal	Status
0	Repo and toolchain	✅ Done
1	Godot JSON runner	✅ Done
2	Tauri bridge	✅ Done
3	Child-facing canvas MVP	✅ Done
4	Sidecar-driven Toybox	✅ Done
5	Asset ingestion (_Inbox watcher, slicing)	✅ Done
6	Smart placement (snap, parallax, z-index)	✅ Done
7	Basic gameplay rules	✅ Done
8	Atmosphere (day/night, weather, lighting, music)	✅ Done
9	Projects and export	✅ Done

What is implemented

• Editor canvas: Mario Maker-style stamp ribbon + Toybox modal, erase by instance_id, drag-paint, pan/zoom, grid snap
• World settings: time-of-day (day/morning/sunset/night) and weather (clear/rain/snow) dropdowns wired into the saved JSON
• Multi-room: save, load, list, delete rooms; Bookshelf picker with mini-map thumbnails
• Auto-save: saves current room every 60 seconds automatically
• Toybox auto-refresh: polls for new assets from _Inbox every 5 seconds
• Godot runner: reads game_state.json, spawns all entity types, applies physics
• Player: move, jump, gravity, heal(), take_damage() with invincibility frames
• Enemies: patrol with ledge detection, damage hitbox, boss mode (scale + speed)
• Collectibles: score pickup, health pickup, pop-and-fade tween animation
• Key-door system: gold key collectibles unlock locked_door portals (color-tagged)
• Checkpoints: override respawn point on touch
• Portals: bidirectional room linking via target_room / target_portal modifiers
• Day/night: CanvasModulate transitions based on time_of_day
• Weather: rain and snow GPUParticles2D systems driven by room JSON
• Lighting: PointLight2D auto-attached to torches, fires, lanterns
• Music/SFX: AudioStreamPlayer spawned from sidecar audio_logic
• Asset ingestion: drop PNG or ZIP into _Inbox/ → BFS sprite slicing → sidecar JSON → Toybox auto-refresh
• Sprite slicing: uniform grid + connected-component BFS with confidence scoring
• Export: zip current project + used assets + runner JSON

Repo layout

/kidgamemaker
├── editor/                   # Svelte + Tauri desktop editor
│   ├── src/
│   │   ├── App.svelte         # Main canvas editor
│   │   ├── ToyboxModal.svelte # Asset picker modal
│   │   ├── BookshelfModal.svelte # Room/project picker with thumbnails
│   │   └── lib/canvasState.ts # Shared types and state helpers
│   └── src-tauri/src/
│       ├── commands.rs        # All Tauri IPC commands
│       ├── inbox.rs           # _Inbox watcher + asset classification
│       ├── slicer.rs          # PNG sprite sheet slicer
│       └── lib.rs             # Tauri setup
├── engine/                   # Godot 4 runner
│   ├── scripts/
│   │   ├── Main.gd            # Entity spawning, room loading, gameplay systems
│   │   ├── PlayerController.gd
│   │   ├── SmartEnemy.gd
│   │   └── Collectible.gd
│   └── data/
│       ├── dummy_level.json   # Example room for testing the runner standalone
│       └── assets/            # Sidecar JSON folders per asset
├── _Inbox/                   # Drop assets here for auto-ingestion
└── docs/                     # Architecture and roadmap

Local Start

Editor

cd editor
npm install
npm run tauri:dev

The editor loads the Toybox from engine/data/assets/. Pressing Play writes engine/data/game_state.json.

Godot Runner

Open engine/project.godot in Godot 4.x and run the main scene.

To test a JSON file after exporting a runner binary:

.\engine\Runner.exe --level-json .\engine\data\game_state.json

Adding assets

Drop any .png, .wav, .ogg, or .zip into _Inbox/. The Rust backend classifies, slices (for sprites), generates a sidecar JSON, and moves the asset to the correct engine/data/assets/<category>/ folder. The Toybox refreshes automatically within 5 seconds.

Key-door system

• Place a Gold Key collectible → player picks it up silently
• Place a Locked Door portal → flashes red if player has no key, opens (with a scale tween) and optionally links to another room if the player has one
• Key colors (gold, red, blue, silver) are matched by tag — e.g., red_locked_door.png requires a red_key

Still to do

• Build and export engine/ in Godot 4 → Runner.exe (manual Godot step)
• Real pixel-art sprite assets (current PNGs are 1×1 stubs)
• HUD overlay (score, hearts) rendered in Godot
• Published installer / app bundle