Since my husband was diagnosed with Alz, I have been hypervigilant about my own cognition (common among caregivers!). I play sudoku, a couple of types of solitaire, and I work crosswords on two sites. Everything is timed, and I track (competing with myself is a lifelong habit), and that tells me if I'm more or less distracted. So far, memory is good.
I have never played games at work, even on breaks, but when I am home.... that's another story.