So Proto-Namic's phonology is usually reconstructed (here presented in transcription as we can't know what it sounded like as it wasn't written) like this:
*p *t *c *ṭ *c̣ *ť *č *k *k° *ʔ *ʔ°
*b *d *ʒ *ḍ *ʒ̇ *ď *ǯ *g *g°
*m *n *nz *ṇ *ñ *ŋ *ŋ°
*v *s *z *ṣ *ẓ *š *ž *x *x° *h *h°
*w *r *l *ṛ *ḷ *y

*i *e *o *a *į *ę *ǫ *ą *i°

Now there are of course some branches, one of them is Namican proper. Its defining features are the collapse of the retroflex and palatal series into one, desibilation of the only sibilant nasal and a vowel chain shift (usually called the Namican vowel shift) which went smth like this: i° o i~ e~ o~ a~ -> y u a i: e: u: a:. The most prominent language of the Namican branch is of course Namic /nɛmɪk/, which has acquired a rather marginal tonal contrast through the collapse of the voiced and voiceless stop series.
Another branch is (of course) still unnamed, so we'll call it Whatever for the purposes of the post. I'll elaborate on that one later when I'll actually have some PN words, so - watch this space.