Actual search is capped at abou 60 results. You need to select tags in the tag search box. I stumbled about this too. It read Search for games, but it should read Search for game titles. Yeah, yeah, it noe also shows search for tags, but this only adds to the confusion. It does search for suggested tags. It does not search for game by tags. So if you searh https://itch.io/search?type=games&q=turn-based it will show you the related tags
Turn-based
Turn-Based Combat
Turn-based Strategy
Card Game
plus games that have this in their title.