Well, I didnt make it to the boss. I kept trying harder and harder rooms and got loaded up with skeleton arrows. Those things hit hard!
This is a fun take on the deckbuilding genre. Excellent use of your assets here - this is a really nice package. However, the font gets old... really quickly. I tried watching the credits and my eyes stopped being able to parse the text after a few seconds. It's really hard to read. To a lesser extent, this applied to the game text, too. For example, I didn't know the symbols in the 3x2 grid were ones until I saw a rune with a 3 in it. The health is tough to read, too.
Overall, very fun. Well made!