Make your own Game Boy games with AI: OpenAI sells a $200 handheld with Codex

What's going on

Since November 9, 2026 (US time), OpenAI and console maker ModRetro have been selling the ModRetro Chromatic: Codex Edition. It's a handheld console in a transparent shell that plays Game Boy and Game Boy Color games. The twist: with OpenAI's coding agent Codex, you can build your own games, even with little programming experience. Then you write them to the included cartridge. The console costs $200 and is available in OpenAI's official online store, "Supply Co."

The device first showed up at OpenAI's DevDay developer conference on September 29, 2026. According to Resell Calendar, around 2,500 attendees received a limited "DevDay Edition" for free. The new version is the retail model with its own design.

How you build a game with Codex

Codex is OpenAI's AI agent for programming. That means it writes and changes code on its own across multiple steps. The console gets its own plugin, an extension called the "ModRetro Chromatic Plugin". According to Habr, it works like this: you describe the characters, game mechanics and game world. The AI turns that into a project in GB Studio. That's a well-known visual editor for making Game Boy games without traditional programming. The plugin handles character animations, backgrounds and maps.

You check the result in a browser-based emulator. An emulator is a program that recreates the old console on your computer. There you can select game objects and suggest changes. According to Habr, the agent can even press virtual buttons and take screenshots on its own while testing. According to note.com, you can also stream the game from your PC straight to the Chromatic. Once everything's done, the game is saved as a ROM file, an image of the game, and written to the "Codex Cartridge" over USB. After that it runs without a PC. If you want to keep tinkering, you can open the project in GB Studio and carry on by hand.

Two things to know: for games to run from the cartridge, the console needs a firmware update and developer mode switched on. According to BigGo, the activation code works on up to two devices. OpenAI showcases three example games built with Codex on its website: the plant puzzle game "Seedy's Sweet Garden", the dungeon crawler "Hollow Descent" and the rhythm game "Codex Dance".

The hardware at a glance

The Chromatic isn't your typical emulator-based retro console. It uses an FPGA, a chip whose circuitry can be configured to replicate the original Game Boy hardware. That's why real cartridges run without software emulation. ModRetro was co-founded by Palmer Luckey, the creator of the Oculus Rift VR headset.

ModRetro says the display maps pixels one-to-one, just like the Game Boy Color. The standard Chromatic has a magnesium alloy shell and comes with either Gorilla Glass or sapphire glass. It costs $199.99 from ModRetro. Since October there's also a transparent model for $149.99 that comes with a Tetris cartridge. The Codex Edition uses the same plastic shell. For about $50 more, you get the Codex integration and the rewritable cartridge.

Availability, shipping and resale

According to Habr, you can order from the US, Canada, the UK, the EU, Japan and New Zealand. BigGo adds Australia. Payment is in US dollars. The store calculates customs and import duties at checkout depending on your country. For Japan, BigGo cites shipping costs of $30, with orders of $125 or more qualifying. The sources don't give concrete figures for the EU. According to Resell Calendar, returns aren't accepted.

The sources disagree on how scarce the console is. Habr and BigGo report that the first batch sold out and that sales will resume on November 19, 2026. Resell Calendar, on the other hand, saw the device still available 45 to 50 minutes after launch. The site concludes that it's made to order rather than produced in a fixed, limited run. Stock probably ran out later on. That's bad news for resellers. The free DevDay units fetched between $800 and more than $1,300 on eBay because only about 2,500 of them exist. Resell Calendar advises against buying the Codex Edition to flip. For retro fans, though, it calls it "a fun buy at a fair price".

Our take

Technically, the console isn't a revolution. What's interesting is the idea: OpenAI is bringing its coding agent to people who would never otherwise write code, through something almost everyone likes, video games. A game you dreamed up yourself, running on a real cartridge in a real console, feels more tangible than a web app. ModRetro is pairing its strength in faithful retro hardware with generative AI.

Plenty is still unclear. The sources don't say which Codex subscription you need for game development or what it costs. So far, how good the AI-made games really get is shown mostly by OpenAI's own examples. Independent tests with lots of users are still missing. The workflow also depends on the project landing in GB Studio. So the Game Boy's limits, such as few colors and low resolution, apply to AI games too. For learning, that can be an upside: projects stay small and manageable. If you already own a Chromatic or an old Game Boy with a flash cartridge, you can use GB Studio without this bundle. The Codex Edition is mainly a convenient all-in-one package with a nice-looking shell.