Disclaimer: I haven't listened to the other movements, but I will in time.
I echo what @malumCompositorsaid about a lack of structure. You have some good ideas here and there, but they seem to be severely disjointed. Try to not to cram everything at once. I did like the motivic figure and its subsequent development from measures 9-16.
There are also a lot of questionable harmonic/melodic choices...For starters, the key signature at the beginning is in C minor, but the material is in G major...and it mostly stays in the G major/minor-ish tonality the rest of the piece. There are odd harmonic progressions (the last few measures of the movement for example), harmonic clashes (flute/oboe around 97, B natural in bassoon at 96)....even if intentional, sound very odd.
Your string writing is alright. Wind writing on the other hand needs more polish. Overall, a little orchestration studying might be helpful, just to get a general idea of the capabilities for each instrument.