Very interesting concept and I liked the story you added. I think it can add to the overall gameplay experience when you are given a reason on why you need to do something, and the story about the mice shrinking items for their own den made you even more invested in your actions. Also, I think that the text you added once you grabbed an item was quite funny. And the fact that this text changed depending on what that item was is also a very nice addition.
One potential thing I would work on in the future: I would probably make the dryer that shrinks the items, as well as the den where you need to deliver these items, a bit more visible (maybe make them glow or add some arrows pointing towards them), especially the first few times you grab something.
The graphics were good and they suited the game, and the music was also well-suited for the experience. Bonus points for adding a button for mouse squeaks :)
Great job!