Most of 2 is just a rehash of 1. 1 flows better as a complete story and is a tighter script and doesn't rehash anything else from another movie. 2 exists solely to get to three, something the director and writer have admitted. the most innovative and coolest part of part 2 is the beginning in the future. After that, its just a remix of a better movie and never establishes its own identity. Every character in part 1 has a complete arc whereas that shyt doesn't exist in part 2 since the arcs are saved for part 3. 1 even has the ticking time clock aspect for the plot, which increases the tension and stress and gives us real stakes.