Last night I turned up the difficulty on a tower defense map and went for a higher difficulty achievement as well. It took a few tries, and I learned new things about how the game randomly changes some variables and can make the map much harder or easier. After more than 50 waves and 2000 enemies, I got it down to the last two and was carefully working down their hit points. Then Windows 10 forced an update and reboot. The Microsoft messages seem to imply that I should be happy about this.