Ah yes, the beginning of the Marvel Cinematic Universe. I bet most people who watched Iron Man in 2008 had no idea MCU was going be this huge thing - I certainly didn't. In fact, I went in never having heard of the character Iron Man, and I still thought it was good.

There's a great tonal shift between the first half and second half of the film, transitioning from what seems like a war documentary into a science fiction thriller

Wow, I've never really thought about it those terms, since my mind just lumps it into the superhero genre.