If you've ever played this game you'll be startled that a computer can do so much, and the more you know about writing software, the more amazed you'll be that they managed to build something with such scope. Here's some links if you're interested: https://www.youtube.com/watch?v=gVOiVIXXrPE https://www.engadget.com/2013/11/19/electronic-arts-frostbite-battlefield-mass-effect (I have no connection to EA/Dice).

So what other software is so amazing that you think "its hard to believe they managed to achieve this"?