Love the overall art and aesthetic. Walking through a weird train ride in an endless void playing tarot cards is great. And the card art is really amazing! The tower being a ferret and "mooooooon" had me laughing.
On the gameplay side I felt quite frustrated. As the player I'm doubly blind - first in knowing the value of the tarot cards, and secondly in knowing what my opponent is playing.
Re not knowing the value of my cards - there is some cool hint at verisimilitude in having to "learn to read" your cards by learning the values, but if that is the experience you were going for it needs to be fun for me to fail and learn.
Re not knowing what my opponent is playing - This plays well into the jam theme of pushing my luck, but I do think you need some feedback mechanism along the way. I need something to sweat about and decide if I want to push my luck or not. Right now the decision is binary. If I know my card values and have played high cards stop, if not, keep going and hope I get high cards.
Some other random thoughts - If you want to stick with the blackjack-like point comparison game, minor arcana seem like a natural fit and then you could use the major arcana for some other sort of system, maybe each one has a power that allows you to change the board state in some way.
I could also see the idea of a tarot read playing well with some sort of abstract combo system. "Cosmic Wheel Sisterhood" is a good reference to look at, where they give each card 4 numbers representing is strength in fire, water, earth and air and the sum of each of those determines the choices available to you.
Overall though, great jam game! Well done to all involved!