Simply wonderful. As a product of the war (I'm half Vietnamese-half American), these touch me. I went back for the first time since the fall of Saigon a few years back (I was 3 years old in '75), and realized what my dad had always told me before he died - that the Vietnamese people are the friendliest people in the world (and he was a world traveller). I noticed the same that you noticed and that my father noted when I went back to Vietnam: the happiest people were the ones with little material wealth to speak of; their wealth was in the experiences and interactions with others in every day life. A beautiful thing; like these photographs.
This series elicits fond memories of my travels through Indonesia, Nepal and Thailand some decades ago. I have trays of Kodachrome slides (remember those?) filled with some similar images. Hard not to love dirty faces, snotty noses, bright eyes and those huge smiles that arose from all involved taking a few precious moments and remembering how to play....