I think that&#x27;s a bit of a chicken egg problem, the large game engines need to be everything to everybody, and trimming the executable size down probably wasn&#x27;t a priority in the past since mostly you&#x27;ll have a big upfront download anyway.<p>However, I remember that the first Unity HTML5&#x2F;WebGL demos a few years ago were much smaller, a complete zombie FPS had a 3.5MB upfront download which is actually pretty decent.