As a yogi, it is no secret that I enjoy electronic visual entertainment for brain stimulation. solitaire.org/logic-puzzle-games/ offers a variety of internet games that challenge the user's logic and advanced thinking skills; with more than a couple of dozen classic logic games, my all-time favorite would always be Chess. Much like our daily lives and the challenges that come across, Chess is a thinking game that constantly has you brainstorming several steps ahead, just like teaching a class when I have to sequence one position after another to create symmetry and flow within the body. Improving focus and always learning some lesson, unable to take back moves that have already been made leaves you all with one option, moving across the board. Time has no relevance in the game of Chess and can leave you playing for hours. Also, being one of the oldest games in history, you have the option to play by yourself against an AI that challenges you on a "championship level" scale. That in itself is all the mental stimulation one needs.
A little chess; Anyone?
https://www.skye-yoga.com/blog/a-little-chess-anyone/
https://www.solitaire.org/chess-grandmaster/