i know this post is old, but the search still needs lots of work. i have some additional recommendations:
- ability to exclude genres as well as tags
- ability to filter by game language (e.g., only show games available in english)
- ability to exclude games in your library, games you have rated, and games in your lists from search results
better itch search by kalrog allows you to exclude tags and genres and has language filtering but doesn't have the ability to filter known games (games in your library, rated games, games in your lists).