looking nice!
the minecart has little up and down animation from the top part to the wheels, to help giving the feeling of motion. i guess it is one pixel thingy.
Other small change I’d suggest, is to move the stones down,
to the bottom of their sprite limit, I guess that gives the impression that they cover something, like an entrance or another character.
And the square button it’s kinda abstract for me, idk if I understand they.
That said, those assets are A Tier, very good for usage.