Wow! What a game. I love seeing things like this. I think the premise for the game you made has great potential to be expanded. I found it satisfying to cast spells, and the tooltips were easy to understand once I looked for them. But I wish I knew what the effects of combinations were before I combined them, or at least the ability to discover and log them.
All that being said, fire and water is a BROKEN strat for this game. It means the enemies almost never hit. If you only take extra dice once you unlock a second combination slot, the game becomes trivially easy, since enemies only attack you once you PASS or are out of dice. Similarly, I would love to hear why you wanted to include a pass button? I couldn't find a use for it. Even if I don't like my rolls, I would rather deal 1 damage than skip.
But, all above criticism is very superficial. The game is fun to play and easy to understand. What I do think the game NEEDS is the ability to control audio in game. But, even more important than that, please add some functionality to the end game screen. I cannot quit or restart from there, and was worried I was going to f4.
Great work on this and KEEP MAKING MORE GAMES!!!