I think this is a very well designed game. It feels very complicated at first but tutorial is pretty explanatory for learning the rules of the game. I like the D&D style story telling. The game board is very well designed. This game gave me a very strong MS DOS 90's game vibe, the music the art all of it. You did a fantastic job in the art design. The magic cards, game board, opponents hands everything looks great.
I haven't played too many of these kind of games like deck builders etc. but i know that in these games, there's always this randomness. Some things are determined by pure luck. This game have the same characteristic and that's something i don't particularly like. It plays a great role in this game too. It gets especially annoying when the luck is greatly in favour of your opponent.
It's a very nice mechanic that every boss has a different skill which makes them distinctive. It is fun to play this game, it makes you think and strategize like chess or poker. It's hard to see games like these in game jams so this game is definitely worthy of praise. Also the genre and theme of the game is very unique too. If you impove and polish it further, i think this could be a very succesfull game. Great job and good luck!