Isyan has eight phonemic vowels, only two of which have long phonemic variants (so that would make ten vowel phonemes in total I guess?). Long variants of the other vowels do occur, but (usually) only in stressed open syllables. I won't include diphthongs, because those are a little complicated. None of these vowels are rounded pairs (unless you consider /ø/ the rounded /ɛ/, despite the former being higher. It could easily be considered the rounded partner of /ɪ/ though).
It has 25 consonant phonemes. 26 if you consider either [ʎ] or [ʃː] a phoneme. 27 if both. Even though all consonants but /h/ may be geminated, it is disputed whether /ʃ/ has a long form or not, given there is no minimal pair between the two, but simply allophonic existence. This is a similar case with [ʎ], which can be considered an allophone of /lj/. However, there seems to be at least one minimal pair between /lj/ and /ʎ/: slyota when said [ˈsljoːtɑ] is simply "bubble," but as [ˈsʎoːtɑ] refers to a bubbleberry.
I think I took your request further than you'd want, but whatever
Let's just say 10 vowels and 27 consonants
(as phonemes)