Cool atmosphere and premise, and the music was good. The card designs look good too, and the descriptions were clear as to what effect the cards would have. The game could really do with some SFX though!
As someone who doesn't play many deck-builder / card games like this, i spend a good few minutes on my first turn just aimlessly clicking around the screen trying to work out how to play a card. Especially with some cards need into click on the player, others on a particular monster to target them, and others can be applied randomly. So that would be the area I'd focus on most in future development, finding ways to clearly communicate to the player, where to click, which enemy is targeted etc.
Finally at the end of each round I was given the choice of 3 perks... but all 3 were always the same - Heal yourself to full health, I didn't know whether that is a bug or just a case of running out of time to add other options in in a game jam.
A decent entry with good potential for sure.