Chris Sawyer wrote 99% of the code for RollerCoaster Tycoon in x86 assembly language, with the remaining one percent written in C.
RollerCoaster Tycoon was a beautiful game which still stands the test of time to this day. The fact that a single person was able to build a blockbuster-level game almost entirely by themselves in assembly is a truly impressive feat which very few programmers would even dream of undertaking.
Being a "real" 10X programmer is like being a savant. It's about being FUCKING SMART, and it's about being able to deliver a working, polished product in the same time that a normal team of ten people would be able to deliver it (or in a tenth of the time that a single person might).