335 megabytes is very big for a file that’s going to be downloaded to be played directly in the browser. I highly recommend that you consider making your game downloadable if you have a large game. There’s more information here: https://itch.io/docs/creators/html5#zip-file-requirements
You may want to investigate if you have unomptimized or unused assets in your game bundle that you can remove if you believe that your game is small.