Building a New Nintendo 64 Game in 2026 with a Homebrew Toolchain

Developer Dominic Szablewski built Xibalba 64, a Wolfenstein 3D-style FPS, as a physical launch title for Modretro’s M64 console clone — reportedly only the second new commercial N64 cartridge release since the console’s original run ended, after Bitmap Bureau’s Xeno Crisis port in 2023. The game grew out of a browser demo he made in 2014 and runs on high_impact, a C rewrite of his 2010 JavaScript engine, Impact. Because high_impact separates platform and rendering backends, adding N64 support meant writing a new backend rather than rewriting the engine; the game itself is technically 2D (no elevation), letting it reuse existing physics and collision code much like Wolfenstein did.

The project leans entirely on the maturing N64 homebrew ecosystem to avoid Nintendo’s copyright-encumbered libultra. Libdragon acts as an SDL-like layer over the console’s quirky Reality Coprocessor, providing sprite and triangle drawing, RSP-accelerated audio, and input. Modern tooling made hardware iteration practical: the open-source SummerCart64 flash cart uploads ROMs over USB-C via sc64deployer, the cycle-accurate Ares emulator now models the RDP and RSP closely enough to catch most bugs, and a $10 capture card pipes real hardware output to a desktop window.

The developer notes the tradeoffs of working close to the metal — Ares still can’t reproduce the N64’s notoriously slow memory bandwidth, which only surfaces on real silicon — and shares practical implementation details, including a union-based vec3_t that overlaps a vec2_t so 2D physics functions work without conversion, plus a browser-based level editor and a hot-reload workflow. The initial port took about two weeks, with several more months spent expanding content and optimizing the renderer.