Being browser-based, you wouldn't be waiting to download 100MB+ if it's correctly designed
You'd download a 1-2mb core script bundle that then dynamically lazy-loads resources as required. For example, if Hearthstone were converted to a browser game, you would initially only load the base client, all the metadata and media (e.g. hero SFX, card data, effects, images) would be loaded on the fly as they are required, or pre-loaded at determined points (e.g. load all the data for both players' decks when beginning a match)
You'd download a 1-2mb core script bundle that then dynamically lazy-loads resources as required. For example, if Hearthstone were converted to a browser game, you would initially only load the base client, all the metadata and media (e.g. hero SFX, card data, effects, images) would be loaded on the fly as they are required, or pre-loaded at determined points (e.g. load all the data for both players' decks when beginning a match)