This is one of my favorite games on itch.io, had such a pleasure playing this! Beat it using only "gold mine" card and buying a bunch of more resource cards from shop. Towards the end, I was getting like 3-400 ores every round, and could just reroll the shop until i got more gold mines.
I would love to see more levels, or perhaps an endless mode, where it just keeps increasing. Perhaps, you could make it so every 5 levels is a boss, or something, where you could earn powerups or something more useful.
For balancing reasons, if you decide to make more levels, I would love to have more turns in a level at later stages - when the deck gets too big, you aren't getting through most of the deck in the few turns we have. Also, a way to start a turn with more than 3 energy would be nice (maybe that could be one of the powerups in endless mode)
Anyway, tysm for this game, it was a blast!!