I like this! It's really clever how you used the ? spaces to tell little stories and you used the gates to make sure the player explores and doesn't miss anything. It's short n' sweet and doesn't feel overly drawn-out.
One tiny nitpick though - when I saw the ? space at the beginning of the game, I started looking for an actual box. Then I figured it must be on the gate, but it's locked unless you put coins in, so it's not really a donation xD
Great job with this game!