I'm a bit disappointed that you block picking up cards when the deck runs out - most games will shuffle the deck at that point. Score would have been higher but I kept having to end turns early beacuse I ran out of cards.
the pile is meant to power some game mechanics (like wrench and mineshaft) but it also serves the purpose of preventing infinites, that way i can include some fun spammy draw cards like minecart. otherwise i can't have cards like that in the game, as you could basically beat the game by playing one card infinitely!