Sounds very relaxing indeed. Not exactly what I'd call medieval... certainly has a folk tone to it, but it seems to have a modern influence on the syncopation, harmonies, and percussion (especially the middle section).
The composition is nice- rather plain and simple though. Medieval music would have a lot more in terms of counterpoint with various melodies and "choruses" of instruments. It's strange if you listen to a lot of medieval music, it's actually very complex with what the melodies and countermelodies are doing, often in a very prescribed format, especially as it gets into the Renaissance and the land of ultimate musical complexity, Baroque.
The instruments are well selected, although for a more authentic sound you might want to find some sort of folk harp or bray harp and maybe even some viol samples for the strings to really match the sounds of that era.
The main issue I have with this is dynamic contrast. While I understand you want to keep a gentle ambient mood, most of the music for ensembles in Medieval times was about certain choirs of instruments (e.g. a recorder ensemble with a soprano, alto, tenor, and bass recorder, or a sackbut ensemble, with soprano, alto, tenor, and bass sackbuts, etc.). The largest ensembles were simply multiple groups of these that would bounce the melody back and forth (i.e. the crumhorns would start, then recorders would take over, then sackbuts would take over, etc.). This way, the melody, however bland or boring, would sound new each time. While having samples of these isn't possible (or always pleasant sounding), a similar idea can be adapted for the modern orchestra- passing the melody around between instruments and instrument families. In addition, having the instruments be louder for a bit or quieter for a bit is always a good idea to create more contrast. At least for me, it doesn't make me want to press play again other than for the sole reason of writing this review.
The next thing to consider is a contrasting B section. You DO have a middle part which is rather unlike the start and end (which are clearly both of the same stem), but it doesn't have much to it- it's kinda like a "drum break" when no one is really certain what is supposed to be happening and I think that space should either bring the song into a new key temporarily and a new melody, or at the very least have some sort of interest and melody to it.
You guys definitely have some great ideas, and I look forward to hearing more of your work.
Keep compos(ed/ing)!
-Samulis