Wow there is a lot of potential with this game, I really enjoyed playing this! Aside from the obvious UI touch-ups and more information given to the player (such as which color dice do what) I'd also recommend showing what the player has equipped so far when they're choosing their item reward after a battle.
I still loved what you have here, and am really hoping you get a chance to expand on this game because there's a lot you can do with this and I would love to see the direction you take it! You definitely deserve more plays/ratings
(On that note, I'd recommend including a web build if you can - people in game jams tend to lean away from trying download-only games a lot unfortunately)