It is surprising how much of the humour is based on that old stand-by, catch-phrases. I remember many years ago reading that Spike Milligan asserted that if you did it often enough, you could eventually get laughs from a character repeatedly opening a door and yelling "More Coal!" or something similar. Though I think the lines in Nebulous are genuinely funny. Whenever anyone says something to me in future that references a body part, I shall think of Harry complaining "Unlike you, professor, I no longer have the luxury of a nostril/nose/leg/arm!"
I heartily recommend it, and hope that there will be more (I see rumours of a TV series).