https://playcebo.itch.io/12-word-searches
 
 Technically not even a browser game, it's a PDF that you can save locally and either mark up in a browser (I used the highlighter tool) or print out and use a pen/pencil.
 
 It starts simple but there are multiple layers of puzzle here, but all firmly in the "word search" category of puzzle.  I found it satisfying.