juliograterol/grid-brawlers ? reverse-engineered prompt

Build me a browser based 2D sword fighting game with a retro arcade feel, using Next.js and TypeScript, where the action runs on an HTML canvas. I want a simple menu, smooth fast paced combat, and the original tuning to feel preserved, not replaced with something floaty or modernized.

It should support local multiplayer, plus a single player mode with simple controls and click or tap to attack on mobile or desktop. Make Esc return to the menu. I also want the game to be easy to expand later, so new characters and backgrounds can be added by dropping in assets and updating a central data file.

Please keep the game logic separate from the rendering, so the match simulation is deterministic and does not depend on the DOM. Use the current docs online if you need to, and build it in a clean way that fits a modern Next.js app with React menus and a canvas game area.