Thank you so much!
Speaking on the beginning, the first level of the game shows a specific dialogue, where the boss explains that they are giving you 3 examples of pristine coins, and that they only want these types of coins. This is kind of the tutorial level that explains things, perhaps I should have been way more explicit to get this point across.
On subsequent levels (and this is not explained to the player), the first coin you get is always a good one, so you can begin with a refreshed frame of reference. It's a bit sneaky but I think it's good to not hold the player's hands too much.