The font is not unreadable, but it's really confusing. The O, 0 and D are very similar, the 1 looks like the 7, the Z looks like a 2, etc.. I do think the font is really pretty, but those distinctions are especially important in this game haha.
I was really trying to beat the game lol, it would be really awesome if you keep updating it after the jam. It also reminded me of Take 5, I don't know if that was an inspiration.
Another bit of feedback that I would add, and I think someone else mentioned it, is having the card value display somewhere on the card so that you dont have to hover to see it. An option to auto sort the cards on your hand by value would also be helpful.