I liked this! It was snappy and had a nice interpretation of the theme. Playing as the princess was the perfect choice for this. Getting to help settle the Commander's nerves did feel impactful. The location was great and used the background to excellent effect. The pensive soldier staring off at a city he's meant to protect is a nice way of presenting the conflict of your story. Him doing it the night before battle, when all is quiet is beautiful. It always seems like conversations like these are found in the quiet moments, which you nailed.
It would have been nice to have seen a bit more, visually, for a conversation of such a length. I'm hardly one to talk about art, but what is there is so good - seeing more could have allowed motion, a tactile response to the player's progressing dialogue via click, auto, or the space bar. I also wasn't entirely sure until the end what their preexisting relationship was, though could have hazarded a guess. Fleshing that relationship out while exploring the fears plaguing the Commander's mind would have helped strengthen the narrative. I don't think it's unreasonable to think he would be focusing on the battle but there must be more going on in there. Does he have a family beyond the soldiers he commands? Is this city his home since birth? etc. Details like that would have only served to deepen my connection with the Commander - who I of course want to see succeed but my investment isn't fully there.
As to not write you a novel, I'll end by saying:
Wonderful job! You should be proud of what you made here, because it's great!