Related to This Post, This Post, and This Post. The most recent post I can find has been archived and is unable to be replied to.

The url edit that leafo made 4 years ago appears to work (sometimes, it has been broken more than once over the years) e.g., https://itch.io/games?exclude=tg.horror, but this is only a single tag exclusion and not well known about as it is not part of the filter results list.

Idea: add an 'Exclude Genre' or 'Exclude Tag,' similar to the ways that you can search for them either by adding it to the side bar or a symbol (e.g., "-") next to the tag to symbolize exclusion.