Thirty But Seventeen is a mix of different K-drama genres, like my headline describes. Overall I liked it, but I'll offer a more detailed review below.

Firstly, the story:
The pacing of the story was a bit off, as it progressed reeaally slowly at the beginning, and it was at first a bit difficult to find some of the characters likable/relatable because of it. And towards the ending the pacing became a LOT faster, but if you don't mind that, this drama has quite an interesting story, I really grew to like it a lot. I liked the relationships between the characters, and I liked the bit of mystery that was mixed into this drama that could mostly be classified as a romcom.

Acting/Cast:
I scored this a solid 9. I feel like the casting was really on point on most of these characters, especially the female lead and some of the supporting characters were absolutely incredible. Though I felt like at the beginning the male lead was a bit difficult to approach, I warmed up to him too eventually.

Music:'
This drama had some fun OST songs, I have no complaints but they weren't exactly mindblowingly good either.

Rewatch value:
I never know what to give dramas in this category because I've watched K-dramas for like 7 years and I have only ONCE rewatched a drama, and that was just because I wanted to watch one drama together with my friend that I had seen by myself before. So I just usually score this section whatever don't mind me lol.

Overall:
Overall I scored this 8.5.
This drama was interesting and entertaining to watch, and it had a good cast, but there were some plot points, misunderstandings and story pacing issues that prevented me from giving it a full 10. I still consider 8.5 to be a good score. I absolutely adored most of the characters, and I enjoyed the mystery element in this drama. I think I would gladly recommend this if you like romcoms with a twist of mystery, if you don't mind slight pacing issues.