Thank you for playing! For the demo, I actually did reduce the number of cards in the deck, which I realize might have been a mistake—while developing, I was using a 68-card deck instead of the 40-card deck in the demo. I think going back to the original number will help a bit with the trouble of running out of cards. Either way, I think you're right; it would be fun to have extra cards lying on the ground that you can pick up to add to your deck, and maybe even have a deck refresh that re-shuffles your discarded cards into the pile!
In future versions of the game, I will be adding the Minotaur, which will move directly toward the player when the deck gets down to 15 cards remaining. When the Minotaur catches you, it's game over, so that will prevent the game from simply ending when you run out of cards.
Thanks again!