Alright, I'm probably gonna have the hottest take on here, but I didn't really like OST :I And I'm going to try my best on explaining why. (Keep in mind this is INCREDIBLY subjective, proven by the positive feedback here.)
1. Instruments
This isn't really something that can be blamed, but by using virtual instruments I feel like you lose that true improvisation that your take on the theme is hinging on, now ofc playing and recording actual instruments would be a tall order and kind of lucrative in a crunchtime jam, but I think it would've helped this a lot, not even mentioning how every note sounds the same in the dynamics which I diminishes any interest for me in the solos. (also I just don't like the sounds of the virtual instruments in general, they sound super robotic and bland). Also the articulations feel super limited because of it as well, even if it is Bossa Nova a lot of it is high energy, some falls or scoops would greatly enhance this.
2. Composition
Alrighty, I was SUPER unengaged pretty much the whole way through, to me there was nothing interesting going on in the solos, which if anything should probably be the most enjoyable, everything felt super predictable and generic, I could probably try to sing along with the solo on my first time listening and not get off track in the slightest. And it probably has to do with playing it safe in the solos, it seemed like it always afraid to play a note off key or off chord which prevented it from sounding "Jazzy" in the first place.
3. Solo Sections
I think there was a severe lack of attention to detail in the solo sections, I would've really hoped that there could be more than just the rythym section and the other solo instrument to accompany the solo, like a section of any 3 same instruments (Like three trombones as an example) subtily highlighting the chords would add SO much to it, I think more research on how jazz music usually progresses (such as structure and standard chord changes in Jazz) would also elevate this.
Overall, I'm just kinda underwhelmed by this soundtrack, but that's just me, hope you find something of value from this critique.
(Excuse me for all the edits lol)