What you see was all rendered at 720p (my computer can't handle much more without dipping below 15fps) with a few graphics settings turned up, and some of it has been slightly enhanced in post. I've taken the liberty of adding a lot of the soundscape myself, from the booming footsteps to some of the screams and noises, but other than that it's in-game audio.
The giantess is exactly 50 feet tall, as the title implies, and I found it quite exciting to truly see how a person at this scale interacts with the city around them. Initially she is my typical female avatar; athletic, red-haired ponytail, wearing clothes I like, often pink ones. In the latter stages, this avatar resembles Alison Hayes in AOTFFW, initially dressed up like in the film (implied by the let's pretend interlude) but later completely nude - as I thought that would be worth a shot. I personally prefer my ladies with clothes on, actually, but I tried to put a bit of everything in, plus if a lady suddenly expanded to this size I'm convinced her clothes probably wouldn't...
The song is 'Arcade' by Hans Zimmer, from the Man of Steel Soundtrack Deluxe Edition
PS: Special thanks to dex_07 on Giantess City for retrieving the video!