Developer Dimillian Builds Daggerfall-Inspired Codexfall with AI Coding Agent Astra

Developer Dimillian showcased using the AI coding tool Astra to take a Daggerfall-inspired procedurally generated game, Codexfall, from nothing to playable, as a test of whether an AI agent can end-to-end generate a complete game world. The game is playable directly in the browser, making it a tangible case study of how well current AI agents can handle large-scale project construction.

Confirmed

Development process: Dimillian first had Astra list all the systems needed to run the game, then asked it to write them into a roadmap document for tracking progress, and finally had it build the first vertical slice containing the foundations of all systems in ultra mode.
Game content: Codexfall is a large procedurally generated world with many systems, featuring numerous towns, dungeons, combat, conversational NPCs, and magic and guild systems — a first-person dungeon crawler themed around steel, magic, and exploring ruins.
End-to-end generation: The game's trailer was made entirely by Astra itself, including the soundtrack; entering any seed on the new game screen generates a brand-new game world.
Iteration approach: Dimillian iterated continuously by playing the game, focusing on polishing fast travel, combat feel, and the first-person perspective.

Why it matters

The project shows that AI agents can do more than write code — covering system planning (the roadmap document), music, promotional video, and seed-based procedural content generation — making it a fairly complete stress test of an agent's end-to-end development capabilities.

2026-09-06 ~ 2026-09-06 · 5 related posts

Full story(2 episodes)→

Episode 1: Dev Uses Astra Agent's Fast Feedback Loop to Polish AI-Generated Game(2026-09-06, 2 posts)
Episode 2: Developer Dimillian Builds Daggerfall-Inspired Codexfall with AI Coding Agent Astra(2026-09-06, 5 posts)

Primary sources

Codexfall: Daggerfall-inspired game built with Astra, towns, dungeons, guilds included — Dimillian · 2026-09-06 03:15 (UTC+08:00)
Dev uses Astra on ultra to blueprint systems and build a game's first vertical slice — Dimillian · 2026-09-06 03:15 (UTC+08:00)
Astra made its own game trailer including music, generates worlds from seeds — Dimillian · 2026-09-06 03:20 (UTC+08:00)

Codexfall: dev builds Daggerfall-style procedural world with Astra — Dimillian · 2026-09-06
[source] Dev uses Astra on ultra to blueprint systems and build a game's first vertical slice — Dimillian · 2026-09-06
Dev iterates Codex-built first-person dungeon crawler Codexfall, playable in browser — Dimillian · 2026-09-06
[source] Astra made its own game trailer including music, generates worlds from seeds — Dimillian · 2026-09-06

1 near-duplicate retellings: Dimillian