putting it together in three hours that is awesome,
when moving the pick axe it got pixelated bad, there was also a split second when you saw the title.
the game play was also very odd, first couple of attempts i was moving the mouse trying to mine as much gold as i could. capping out around a couple hundred, I finally found a sweet spot where i let the axe just go down on its own with no player input and ended up with a high score of 900.
my suggestion would be to require player movement to take away the dirt/gold it felt very passive like i didn't need to be there