Of course, there are plenty of games which offer small puzzle segments (assuming that you are strong minded enough to stop at one or two at a time), but I am never sure which section of the gaming threads is appropriate for those: probably not quite casual, but no other obvious category, so perhaps here...
I have in mind games like Baba Is You, Steven's Sausage Roll, Wormholes, and more recently CATO: buttered cat.
