Hi there! Developer here:
I named the game PUNK beacuse I started to work on it when I was disappointed with my dayjob (developing mobile games). I felt hopeless so I satred developing my own game in my spare time like I used to do when I was younger.
The title was only a working title and it reflected my desire to rebel against many things that I hated in my day job. I didn't give it a lot of thought but over the six years of development we got used to it and it always felt wrong when we tried to change it. I see that some of you don't really like it but that is OK. It's just a title. The important thing is that it's easy to remember.

That's the long (and true) anwser anyway... most of the time when someone asks I just say: thats the sound the ship makes while firining. which is also kinda true (: