Hey Phil. I hope you're having a great time in Crete

In the meantime please accept an additional pat on the back from Mr Ed (for what it's worth). Just when I think I can't bear to look at another collection of Holga pictures, something like this pops up and makes me change my mind. Colour, composition, grain, punch, awesome skies....a joy to look at and savour and none of the usual dreary Holga fare as alluded to by Skorj in his comment. Well done matey; great stuff.
Also, good on you for sucessfully using the NPZ in a Holga. A few years ago I started using the Fuji NP? range of films in my Holga and I never really got on with them, but you've got the NPZ jumping through hoops for you. Maybe I should have moved up from ASA400 and tried the ASA800? Hmmm.
Anyway, let's see more of you here once you're back from Crete. maybe tell us how you get those incredible, dense, angry skies.