Had me going insane for quite a while when I couldn't find the 5th gold piece, turns out you have some sort of bug where if at the start you decide to mine the ore that's down of the ladder rather than the one to the right, it causes the one on the right to disappear and make the level unbeatable.
Will second the other commenter's confusion on the TNT looking like an interactable element despite only being decorative, but otherwise congratulations on the game, keep it up.