I like the loss of nasals with compensatory lengthening before aspirates, that's kind of a cool touch. As is the behavior of syllabic nasals with respect to stress.

Not much to say about the vowels; I'm never happy with my vowel systems or changes, they always feel wildly derivative, or boring. I need to get back to work on Kuma-Koban in the future; it's literally been like 3 years.