I haven't look closer but my impression is that the gold appear in random places and the amount for finishing a level also is random. IF that is the case, then the only influence the player has on getting gold is clearing as much as possible but not running any risk.
IF all these are random then the gold is kind of irrelevant. It would be better if every tile give the same amount of gold as the danger number, as this give the player a lot more influence on the amount of gold to get. And the finishing amount for each level could be the level times the gold you got on that level. But I haven't studied the gold mechanism so this could be wrong.
Otherwise a very cute game. I would like the sweeper to move faster at long distances, but it is as it is. Apart from the speed a better version of Landmine, the original minesweeper