Thank you for your feedback.
I didn't mention that this piece was supposed to fit the mood of a particular artwork (https://www.artstation.com/artwork/XgBeQL) so it kinda is a soundtrack but i still tried to make it more than that if it makes sense.
About the engraving its clear that i lack a lot of knowledge. The stems facing upward are not from the vibraphone but from the woodblocks, and they were placed like this by default on musescore and i didn't really pay attention to it but now i know how to fix them so thanks for pointing that out. And i had to put the "change instrument" at the start because i started the score with two sets of percussion and not vibraphone and bols chantants (singing bowls?) but i guess i had to plan that before creating the score.
As for the flute i need to read more about it because i don't really understand what you are saying and for the tremolos i don't know why i tied them, i think i added the tremolos afterward so i forgot to remove the ties.
Anyway, i have to learn more now.
Thank you for taking the time to help me.