November 2026 Summaries

ModRetro’s Chromatic plugin for Codex enables users to create, test, edit, and deploy Game Boy Color games through Codex and the GB Studio development environment. After installing the plugin in the ChatGPT desktop app and preparing a local project, users can describe a game concept in natural language, have Codex generate and compile it, and preview the resulting ROM in an emulator with keyboard controls. The plugin supports iterative development through sprite animation creation, map and collision editing, visual annotations, automated input sequences, and integration with GB Studio project files and assets. Developers can also extend games with GBVM or C, use GBDK-2020 for standalone C projects, or build custom engines in assembly using external toolchains. To run a finished game on a Chromatic handheld, users need compatible hardware, a rewritable cartridge, a USB cable, and Developer Mode; installing a new ROM overwrites the cartridge’s existing game and may erase saved data.