Let me start by saying that this game is really amazing to play! The amount of work that went into making the game as appealing as it is is just astonishing! The mechanics are very deep for a game jam game, and I can imagine it being expanded into a larger game. It doesn't feel real that this is a game made in a game jam :).
I just have some small criticisms of the game, but they are more nitpicking honestly.
The first is regarding balance. There is no way to gain health in between levels, however, the enemies grow in strength every turn. Because of this, the last level is almost impossible since you start with very little health.
The second is that the game feels a bit too generic. Lovecraftian themes could also have been incorporated into the cards and mechanics of the game, instead of just the Lovecraftian makeover on the enemies.
Other than that, this game is absolutely fantastic and I really enjoyed it from start to finish :)!