Codex Mortis is making waves in the gaming world. It boldly claims to be the first game entirely created with AI. Developed by Grolaf, or Crunchfest, this game took just three months to build using 100% AI-generated assets, code, and music.
The artwork came from ChatGPT, while animations used a shader crafted by Claude Code. Surprisingly, no traditional game engine was involved. Instead, the developer wrote everything in pure TypeScript. They relied on PIXI.js for rendering and bitECS for the backend, all wrapped into a desktop app using Electron. Grolaf described the process as “vibe-coded,” leaning mostly on Opus 4.1 and 4.5.
In Codex Mortis, players take on the role of Death. The game invites users to mix different dark magic schools, unleash powerful spells, and command undead armies in a thrilling bullet hell experience. With endless gameplay options, it supports both solo and co-op play. The developer emphasized that the game’s development was a leap into the unknown, starting with a rough prototype to test feasibility.
Creating a consistent art style posed challenges, but Grolaf noted that GPT helped maintain it across sessions. Character animations didn’t quite land, leading to shader-based wobbling instead. Grolaf found this approach much less draining than traditional app development, comparing it to an exoskeleton for a construction worker.
The game hasn’t launched yet, but discussions on its Steam forum are lively. Threads like “This looks like ass” and “Garbage AI slop” reflect mixed feelings. Interestingly, many users express skepticism about the use of AI in game development.
Meanwhile, the AI game development community on Reddit showcases a slightly warmer reception, although many comments have been removed. Recent statistics show that over 70% of developers in a survey feel uncertain about AI’s role in game design, illustrating a split in opinion within the industry.
For those curious, a free demo is available on Steam, currently holding a ‘Mixed’ rating. One reviewer humorously noted that the demo was “worth the price.”
As the conversation around AI continues to evolve, how Codex Mortis performs upon release could be pivotal in shaping future developments in the gaming industry.
