"simple" ;-)
Well, it is trivial to modify the page on client side. Based on the information the client has. The main genre is displayed, so yeah, that one could be filtered. Will not work for secondary genres (genres selected as a tag).
You can put your code in a bookmarklet, instead of using the console. Unfortunately the genre is not selectable by css, otherwise you could use a user style addon, as you could do to filter developers or items.
I made a tampermonkey script, if you want to test it. It is the whole other reply, for easy copy pasting. I made a similar one for filtering items and even have an unpublished extension, but quite a lack of interest, despite there being so many threads about filtering.
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Oh, and that tampermonkey script sticks and it will filter out genres on search pages, but there is no button on a search page to deactivate it. You need to go to a browse page to remove the filtering. Hence the differently colored button. If you use display:none as a style, you will not even notice that the filter is on in endless scroll mode.