Some 2.3 million of U.S. adults older than 65 — more than 4% — have a diagnosis of dementia. But even without a diagnosis, a certain amount of cognitive decline is normal as age sets in.

Real-time strategy games are a lot of fun to play alone or with friends. Here are some of the best games in this genre that support co-op campaigns.

The game was developed by Danish studio Slipgate Ironworks and Polish studio 2B Games. In its Steam page, the developers said it was "inspired by RTS (real-time strategy) greats of the 90s and 2000s." ...