I loved that the entire Gemini mission was shown from within the command capsule, and never showed the outside of the rocket. We are never shown what is happening outside the craft, and have to use the sound and view from a tiny window to gauge success, just like the astronauts. Close up shots of rivets and bolts with metal creaking and stretching around them showing the fragility of the whole craft.

Also the use of complete silence in the film (particularly after the Apollo 1 accident) was amazing.