Yay, you got it submitted!
Something I appreciated was how every lock was unique so the gameplay stayed fresh, even though it was really simple. The audio cues were well used and effective. A very nicely made game.
A tip for pixel art is to make sure that all of your pixels are on the same scale, for example in this one pixel in the hand is bigger than one pixel on the dial lock which is much smaller than the pixels making up the folder. This means in Unity to make sure that no gameobject with a pixel art sprite renderer should be scaled and that every sprite should have the same pixels per unit. Having every pixel the same will make them look a lot better. (Make sure to them measure the canvas size you need before you start to create the art so that you don't create something the wrong size and have to redo it (more work) or scale it (looks bad)).
Sorry if that was a bit much, literally a tiny nitpick and not affecting my rating at all, just something to consider.