What is a video that you did not expect to take such a s udden and very dark turn?

Depends on when you played it. It came out in a decade of generic war shooters (including other spec ops games) so the subversion slid under most people's radar, which was intended. There are subtle hints as you play, but iirc the scene described above was the first time the game really slaps you across the face.

It took a few years for the game to gain a cult following and recognize it for what it is. Nowadays the only people who go back to play it already have some idea of what they're getting into.