Looks a bit too much like a clone of slay the spire, but a nice game nonetheless - I am impressed how much you managed to achieve in 48 hours. Good job on making all the card cover-arts! The slime boss is fun, those animal head sticking out :)
A few things to improve upon:
1) The fire on top of the stick of the player is a lot more detailed and hence looks out of place.
2) The card that says "draw a card, discard a card" should probably specify that it discards a random card.
3) Obviously, you can improve UI by looking at slay the spire - add the ability to look into draw and discard piles, add buttons for fast card picking (and E to end the turn).
4) Looks like none of the enemies have any abilities, that is kinda sad.
5) Add some more animations to both player and enemies - they kinda just stay still the entire combat.
6) I'd say remove the "next turn draw two extra cards" card - it is pretty much useless. The only time you would play it is if your hand is full of healing cards you can't play and you just happened to have spare energy left.