# Hyakki Yako (百鬼夜行) — NEON PRECINCT sample game

**English** · [한국어](README.ko.md) · [日本語](README.ja.md)

As of 2026-10-03 · Engine team · release bundle `samples/hyakki-yako/`

A beat 'em up sample made with NEON PRECINCT. Play it as is, open it in the tools and edit it, or use it as the starting point for a new game.

## What's inside

| File · folder | What | Open in |
|---|---|---|
| `hyakki-yako.html` | Built game | Browser |
| `hyakki-yako.game.json` | Game package — characters 7 · stages 2 · obstacles 7 · items 4 · game settings. Includes art · sound | Game Forge “Load game JSON”, loading in the engine on its own, Stage Forge enemy list |
| `edit/characters/` | One character per file, art included | Character Forge |
| `edit/stages/` | One stage per file, art included | Stage Forge |
| `edit/obstacles.json` · `edit/items.json` | Obstacle · item definitions | Asset Forge (create · edit), Stage Forge steps 8 · 9 (load and place) |
| `source/` | Originals — data (`src`) and art · sound files (`assets`) | When reusing art · sound |

`edit/` and `hyakki-yako.game.json` carry the art inside the files, so they open directly in the tools. `source/` has the art as separate files, for reusing it.

## Text languages

The text written in the sample files (stage names · wave hints · character names · cutscene lines · credits) is originally **English**.
The game also appears in Korean · Japanese to match the player's language — translations are in `i18n` of `game` inside `hyakki-yako.game.json`,
and you can export them with Game Forge “◇ Translation sheet” to edit or add languages.

The opening video has its subtitles burned in, so there is a file per language. The built game contains the **English version**;
the other versions are `opening_<language>.mp4` in `source/assets/cutscenes/`. Swap one in with Game Forge “6 Presentation → Intro video file”
and build, and you get that language's version of the game.

## Making a new game

1. Copy this whole folder and rename it.
2. Open `hyakki-yako.game.json` in **Game Forge** and change the title · cutscenes · music · credits.
3. For characters, open files in `edit/characters/` with **Character Forge**, or make new ones with **Sprite Forge**.
4. For stages, open files in `edit/stages/` with **Stage Forge**. For obstacles · items, open `edit/obstacles.json` · `edit/items.json` in **Asset Forge** to edit or create them, then load them in Stage Forge steps 8 · 9 and place them in step 7.
5. In **Game Forge**, gather the edited files, add the engine file and build — you get one new game file.

## Usage scope

You may **use the art and sound in this sample in your own games.** Commercial use is allowed,
and so is modification. **No credit is required.** However, they may not be used for the prohibited uses below.

### Prohibited uses

- Any use that violates the law
- Exploiting or harming minors
- False information intended to harm others
- Generating or spreading personal information that could harm others
- Defamation · harassment
- Discrimination or exploitation of vulnerabilities based on age or social, physical or mental characteristics
- Medical advice or interpreting medical results
- Generating information used for law enforcement · immigration · asylum decisions
- Fully automated decision-making that affects people's legal rights
- **Training AI models with this art and sound**

These conditions stay with the art and sound when you pass them on to others.
When you do, please pass this section along with them.

### Engine · tools

The NEON PRECINCT engine · tools · scripts are under a **free license** — The engine · tools are free to use when downloaded from the official distribution channel (neonprecinct.com), and games you make can be sold freely with no royalty. Reselling or redistributing the software (even unmodified or free of charge), distributing modified versions, and distributing it under another name are not allowed — engine files included in your games are the exception. Sharing a link to the official channel is fine. See `LICENSE` at the top level.

## How this sample was made

| What | How |
|---|---|
| Character · effect · cutscene · title art | Made with generative AI (Google Gemini), then touched up |
| Obstacle · item · background art | Made with generative AI (PixelLab), then touched up |
| Some effects · marks | Drawn directly in code |
| 12 sound effects | 6 from Kenney (CC0) · 6 synthesized by us |
| 4 music tracks | Generative AI (Google Gemini) |
| Opening videos (Korean · English · Japanese) | Video made with generative AI (Google Gemini), with subtitles and the ending edited |

Per-file records are kept in our private development repository and are available on request.

**Use of generative AI** — Portions of the artwork, sound, and English/Japanese translations in this product were created with the assistance of generative AI tools.