I'm completely addicted to this game... I've always had a love of deck-building board games. But the UI and rules are so simple that anyone without previous knowledge of the genre can pick it up!
Can't seem to get past the Gassy Bat (a combination of the bombardment of monsters from the "market" deck and her high attacks leave me dead before I have the chance to collect good cards)
It would be interesting to see if the "deck" you crafted from one boss carries on to the next one allowing for greater difficulty curves along with a sense of progression (or maybe you choose to keep 5 cards from that boss which is added to the "starting" deck).
Overall this game was really fun to play!