You don’t want your browser to hog your resources (i.e. your precious memory) unless you’re specifically playing a browser game.
Chromium-based browsers: chrome://settings/system
Firefix-based: Peformance category in about:preferences#general
Also, if you’re attempting to play on Firefox or other derivatives, but the game is failing to run, check about:config and search for javascript.options.wasm, as it is required to run modern Unity browser games. Please disable it afterwards if it was. This doesn’t apply to Chromium as it requires modifying launch options. At that point, you know what you’re doing unless you share my forgetfulness.