This dungeon was great! The art and atmosphere was awesome, movement mechanics spot on and the combat was, while simple, was enjoyable. I did play through a second time to let the timer run out and see if maybe there was a secret fight, there wasn't but that's ok.
I think there could be some tuning to the combat, I initially died as the enemies scale up basically with each fight and I ran out of cards fighting a ghost who healed a bunch. I found simply pumping up the damage on the 3 damage chicken card was the path easiest path to victory. Maybe some sort of resource mechanic that allowed you to use multiple cards or if cards had multiple effects (shield + attack) might add another dimension to combat where it almost never seemed useful to heal or use a shield due to not being able to do anything else.
Overall solid entry. Well done.
Gameplay here around the 30s mark