"A roguelite deckbuilding adventure game about magical coins. You play as a lootmancer, who can unlock the hidden power inside of coins and use them in magical duels. The loots you take from chests and enemies also become your next moves, so plan carefully!"
The copy/pasted blurb means, of course, that I can't personally vouch for this one, but reviews are very positive both on Steam and around the internet.
As per usual, you'll need to chuck in a minimum of $0.25 for a DRM-free download, or $1 for a Steam code. Considering that the RRP is £6.99, you're guaranteed a saving, though you should of course give what you can.