This is such a great premise and the angel is soooo charming and definitely should be trusted with your soul. You did a great job writing her and giving her a lot of personality and good little quirks!
On the other hand, I think that parts of the story suffer a little with how hollow the soul is. I get that the protagonist of this story has to be like that, but I had a hard time getting invested in her and I feel like it drags down the pacing some.
But then the twist with that is really clever and exciting! It's a very compelling way for their interaction to end. I wish there had been more focus throughout on the specifics of the soul repairing process (how does it feel? what happens at the moment when a new piece is slotted in?), because it is such a good and juicy premise.
The presentation is also really strong - the angel is so cute and with so many different sprites it always feels like she's emoting exactly as she should for whatever she's saying. Great work doing that all by yourself! The music fits very well too.
Good for her :)