I left my machine running with the game on the menu... I know it runs pretty crazy frame rates but that shouldn't really kill anything. I came back inside after a couple of hours of doing chores and started a scenario to find that the menu is burnt into my screen. Hopefully it will clear while the monitor is off but if it doesn't my $800 photo editing monitor is now stuffed and I am very sad. So a word of caution, don't leave the menu running. Note I'm not suggesting this is the game's fault... any bright static imagery will do it apparently.