You can reduce all of your model files included character meshes' tris count to optimize your web game.
Have your game all sprites in seperated files? It's not good for web games. With Sprite Packer, you can pack all of your single sprites to 2^n powered atlas.
Check all assets including materials, sprites, model files in your scene and optimize them to reduce memory usage and file size for your build.
Unity WebGL games can be played on mobile with Hyper Web SDK templates.
Unity's Brotli compression allows to compress game extremely without quality loss.
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