Gravity is the latest "isolation" movie that follows one person's--or in this case two people's--terrifying battles against harsh, stark, nature.
Think Castaway or 127 Hours or any of the Twilight movies (in this case you, the audience member are the one stranded in isolation).
The difference with Gravity, starring Sandra Bullock and George Clooney, is that it takes place in space. Everything's way more terrifying in space.
Check out the first Gravity poster: