Any good recommendations for games that you can play while multitasking or require low effort?

I'm working on some things on my computer but at the same time would enjoy a game - but most of them require your absolute attention.

Are there any good low-focus type games you play while you're busy? Or on your second monitor if you have one?

Some examples would be something like Solitaire, Chess, Minesweeper - just games you can take your time with and don't need you glued to the screen.

Any good recommendations for games like this?