It's possible, see this forum post.
I feel strongly that it needs to be easier than that.
We really shouldn't have to scour for the solution and then have to affix ?exclude=tg.horror every single time we go to another itch.io page. Plus, you can only exclude one thing at a time, so its sometimes super frustrating when you're searching for more specific game types.
At the very least, I'd at least like to be able to block or hide games/thumbnails from the feed.