So, your question is, how to do this or is this just in the wrong section. This is questions and support.
Genres are regular tags. The only difference is, that in the url they are written as genre- instead of tag-. But they function exactly the same as tags. A game has 1 main genre and 10 tags, You can set all of those 11 tags to be "genres".
For randomly browsing you can use the randomizer /randomizer but it cannot filter by tags. Randomly browsing top games with the vague description of not liking visual novels is tough. A lot of games use visual novel as a tag, but are not actually visual novels. You will miss those surprising games. And a lot of games are story rich or have a lot of text and are not tagged visual novel.
So for the 1.5 million games here, it is a lot easier if you select a tag or two. Like action, or puzzle. Or whatever you actually like. Everything but visual novels is a bit vague.
Anywy, the main genre is displayed on the browse page, so they can be filtered easily client side. I made a script for that. It will not filter away all the visual novels, but at least the ones that do have it as their "main genre". I made another script (same page, no screenshot) to make games disappear, on the press of a button. This way at least you only have to look at them once.
You can also use the undocumented feature to exclude 1 tag. Pick your standard filters, add the ?... and put it in a bookmark.