For whatever reason, when i am in the middle of second scenario(persians vs spartans) my screen and audio would just freeze with no signs of coming back to life. Now, i had similar issues playing TW Warhammer 2 and it was purely my fault as the issue lied in my CPU overheating. But since then i fixed the problem and TW2 worked just fine. Of course i checked whether CPU started to feel bad again and utility program shows around 55 to 60 degrees celsius.