Nice work, it's a nice composition.
Constructive:
The reverb is too dry. Don't be afraid to make it wetter, especially with ambience.
The strings will sound a lot better if the beginning of one overlaps with the end of another, creating a more smooth transition that sounds more realistic.
The orchestral aspect of it isn't want makes it feel less like ambience - the composition sounds like it is an introduction/reveal more than ambience. Ambience can take a lot of directions, like movement.
Nicely done.