There is a little great book called "Godel's proof" by Nagel and Newman[1]. And definitely requires some focus but readable nevertheless.
[1] https://www.amazon.com/G%C3%B6dels-Proof-Ernest-Nagel/dp/081...
Edit : removed a line
[1] https://www.amazon.com/G%C3%B6dels-Proof-Ernest-Nagel/dp/081...
Edit : removed a line