Project Ashfall
Seed enemies with ash, then stitch through the marked ones in one line and blow it apart. A top-down roguelite prototype implemented, tested and self-reviewed by Codex.
Links go to the official store or developer page. Last verified Nov 7, 2026.
Where to play
Every platform this game is on. Links are checked against official sources; we never host or mirror games.
- View demo on itch.ioitch.ioDemo · Prototype v0.8.1, in developmentFree
Plays in the browser on itch.io. No download.
Browser (no download) · Official link verified Nov 3, 2026.
About Project Ashfall
Project Ashfall is a free top-down action roguelite prototype for desktop browsers, in Japanese and English. Your shots fire automatically and leave ash marks on enemies; left click or Space triggers Ash Stitch, a dash along the aimed line that collects the ash and detonates every marked enemy on the path. Stitching three or more marked enemies at once is a Triple Stitch, for crowd control; collecting six or more fresh ash from one or two enemies is a Dense Stitch, for burst damage; upgrades such as Return Stitch and Chain Stitch add follow-ups. Blue embers level you up, with 22 upgrade types across 55 levels, guardians at three, six and nine minutes and a final boss at twelve, so a run takes about 12–16 minutes; Ember Sigils earned across runs unlock a starting loadout. It plays with keyboard and mouse (no gamepad or touch, no mid-run save), and progress is saved in the browser. The developer, who writes on Qiita as Masato_Iwasaki and publishes on itch.io as mapyojojo, started it at home after subscribing to ChatGPT Plus: the first brief, drafted with ChatGPT, left game design details and the tech stack to Codex and asked it to build, test, fix and self-review a playable prototype. Since then the developer plays each version and decides, ChatGPT turns the feedback into prompts or sprint plans, Codex in VS Code implements and tests, and a separate AI conversation does QA. Graphics are drawn on canvas and the sound is generated with Web Audio. Version 0.8.1, still in development; the source is visible on GitHub with no licence.
How it was built
VerifiedPer the Qiita article (19 Oct 2026), the first request, drafted with ChatGPT, asked Codex to turn a small action roguelite into a playable prototype, leaving game design details and the tech stack to Codex and having it build, test, fix bugs and review its own work (“ゲームデザインや技術スタックの細部はCodexに任せ、動くものを作り、テスト、不具合修正、自己レビューまで進めてもらう”). From then on the split was “設計は私とChatGPT、実装・テスト・自己レビューはCodex” (design by me and ChatGPT; implementation, testing and self-review by Codex), using the Codex extension for VS Code. Later the developer set up roles (Human Producer, Director, Implementer, Game Design Reviewer, QA Reviewer) with shared rules in AGENTS.md and a sprint file, so a short instruction to read them starts the work; Codex is the Implementer, and a separate AI conversation acts as QA Reviewer. Codex also built a developer debug UI (v0.8.0) that public builds disable. The developer decides what to build, plays, and accepts or rejects results; merges, pushes, tags and publishing are done on the developer's explicit instruction.
- DeveloperThe repository's AGENTS.md tells Codex to work as the Implementer by default from the current sprint file, and the README describes the automated tests, browser checks and the public-build script. — GitHub
Helped write the first request; turns the developer's play feedback into prompts for Codex; proposed the five-role setup and the shared Markdown and sprint files; acts as Director, organising goals and scope and summarising review results.
Browser game drawn on canvas, with sound generated by Web Audio and no runtime libraries, bundled assets or audio files. Codex (VS Code extension) implements, writes tests and self-reviews; ChatGPT acts as Director; another AI conversation reviews as QA; the developer plays each build and decides. Shared rules live in AGENTS.md and plans/current-sprint.md. Electron and Tauri Windows builds were prototyped in sprints 1–2 and put on hold. A PowerShell script packages the itch.io ZIP with developer modes locked off.
- Engine / framework
- None (vanilla JavaScript)
- Languages
- JavaScript
- Team size
- 1 (solo)Developer ReportedQiita (Masato_Iwasaki)
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
“設計は私とChatGPT、実装・テスト・自己レビューはCodexという分担で、このやり取りを続けていました。”- Making a game with Codex turned into running a small AI dev team (Qiita, Japanese)
- Source on GitHub (mapyojojo/project-ashfall, no licence)
Verification notes: AI use and the workflow come from the developer's Qiita article, shown as posted and updated on 19 Oct 2026 (its metadata gives 14 Oct 2026, 14:00 JST as the first publication), re-read with its Markdown source on 7 Nov 2026; it links the itch.io page as the game the article is about. Mechanics, controls, version, run length, browser support, the language field (Japanese/English) and the AI disclosure (AI Assisted, Code, Graphics, Sounds, Text) come from the itch.io page, last updated 9 Oct 2026, 16:09 UTC, status In development; the itch.io page links the GitHub repository. The README (read through raw.githubusercontent.com) adds the guardian and boss timings, the canvas and Web Audio approach, the public-build script and the statement that no open-source licence has been chosen; the source is published for reference only. The article says Codex did the implementation, testing and self-review; it gives no code share. Team size 1 reflects “自宅PCで個人開発” (solo development on my home PC). The developer is identified by the Qiita handle Masato_Iwasaki and the itch.io account mapyojojo; no other personal details are recorded. The first public date is not stated. The game's script makes no AI calls according to the README (no external communication needed); the code was not audited. No rating or download count is shown. The game was not played.
Development history
itch.io page last updated (prototype v0.8.1).
Observeditch.ioThe developer's Qiita article describes building the game with Codex and an AI review workflow, linking the itch.io page.
DeveloperQiita (Masato_Iwasaki)
Game performance
Each figure measures something different — concurrent players, owners, downloads and sales are never interchangeable and are never added together. Labels show where each number comes from.
itch.io
Free in desktop browsers with keyboard and mouse; tested in Edge, basic checks in Chrome and Firefox, Safari untested. No gamepad, touch or mid-run save.
Not publicly available: itch.io rating, Gross revenue.
Reviews & rankings
Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| Codexでゲームを作っていたら、小さなAI開発組織を回す実験になった Qiita (Masato_Iwasaki) · Japanese | Devlog | Oct 19, 2026 | Nov 3, 2026 |
| Project Ashfall by mapyojojo itch.io | Store page | Not confirmed | Nov 3, 2026 |
| mapyojojo/project-ashfall (README, AGENTS.md) GitHub · Japanese | Repository | Not confirmed | Nov 3, 2026 |
Get your badge
Made this game? Add a “Featured on VibeGameDB” badge to your site, GitHub README or itch.io page.
<a href="https://vibegamedb.com/en/games/project-ashfall" target="_blank" rel="noopener" title="View Project Ashfall on VibeGameDB – the database of AI-built games">
<img src="https://vibegamedb.com/badges/featured-light.svg" width="250" height="54" alt="Featured on VibeGameDB – Project Ashfall, an AI-built game" />
</a>Similar games
