The visuals are for the most part great, sometimes blurring the line between archival documentary footage and re-enactment.
But the movie itself is poorly structured.
For seemingly no reason at all it jumps back and forth in time, making one unsure exactly what happened when, and how much time has passed. I imagine a more linear approach would have been much more effective.
There was a bunch of climbers divided into three groups, but the movie doesn't do a very good job of introducing them, with a few exceptions, making them indistinguishable from one another. Consequently it's sometimes hard to understand who is where on the mountain and when, exacerbating the problems of the non-linear narrative.
It's a pity. This movie could've been great, especially with the documentary footage, but it's lacking in focus.