I just played it, and I have to say I really like the idea. I have seen multiple stacking games so far, but not quite like this.
I also really enjoy pixel art games, and the art in this one is really good.
Small improvements I have:
At the beginning, the Ui was kind of confusing. I didn't realize at first that the objects on the right where just visual and I though I had to grab them.
Besides that, it's a really relaxing, cute game, especially with the music. Good job!