Boxcars[0], a web-based client for playing backgammon powered by Ebitengine, compiles to a 20MB WASM binary[1], and as long as the server and browser are gzip-enabled, this actual transfer size is reduced to a little under a third of this.

0. https://code.rocketnine.space/tslocum/boxcars

1. https://play.bgammon.org