Interesting idea! I haven't played anything else like this for the jam where you have two dice and you need to customize both of them.
If you were to continue working on the game where's what I might suggest...
-I didn't really realize the impact of customizing the dice until I started playing and could see how it worked. It might make sense to throw the player right in and defeat a simple enemy to learn what's going on and then be able to customize their dice.
-I think my character was the card and the enemies changed? It wasn't really clear, I think some depth of field on the camera to blur out the background a bit may have helped. Some really simple attack or damaged animations would help too.
-On the main screen I'm not sure what's a button and what's UI, everything has a really similar boarder. The color schemes as to what's a button, and what's UI don't seem to have any correlation