I’ve studied this a lot. The intent of games, etc. is not just to challenge the brain process, although that has some benefit indirectly, but the strongest benefit is to pursue something that requires your brain to lay down new neural pathways - most commonly associated with learning a new skill. Examples are a new language or a technology skill or learning how to do math like they teach 5th graders today 🙂
Or read what they are learning about what can influence Alzheimer’s onset. For instance there’s a large study of Nuns observed. Clue - add folic acid to your supplements. I will put a link to the National Institute of Health review.
Even working complex jigsaw puzzles work out the brain to an extent. Learning how to make a soufflé is a new pathway for most of us.

Eat like smart healthy people eat (do as I say…), Particularly eating smart fats and ingredients as fresh as you can manage.
Walk every day or multiple times a day
Keep a log of new things you’re learning. It doesn’t have to be calculus (thank goodness for that). It just has to be new enough to your brain that when it can’t find it, the process to lay down new pathways is triggered.

Here’s the link to the Nuns’ study. Goood luck. And I am positive MayoConnect has many discussion threads on this topic.

And here is a link to some good games -
with some discussion.
https://www.chenmed.com/blog/connection-between-brain-games-and-dementia-prevention