Here are several new-to-me free online learning games:
Geotastic is similar to other games on The Best Online Geography Games that show you images of a location and have to identify the country. You can create your own game, also, but friends have to be on the same device to play against you.
Datak is a game about data privacy.
Here is how the Cards Against Humanity describes their game:
In Cards Against Calamity, you take on the role of mayor of a small coastal town. You must balance the needs of various stakeholder groups, from fishermen to tourists and small business owners, while protecting the town from job loss, pollution, hurricanes, and hipsters. Do you have what it takes?