This was so cute to play!
I think having a health bar above enemies would help in seeing how far along you are to defeating them.
Final boss was a bit tedious since it was pretty tanky, I'm wondering if you could implement some sort of ability for the character that can help defeat the boss (any maybe other enemies) quicker. Maybe have other dice spawn on the map that could give the character could roll for a one-time/two-time/three-time ability power. For example, a spawned die has three sides for plasma blast -- one side with one purple blast to mean one-time shot, one side with two purple blasts to mean two shots, and a third side with three purple blasts. Repeat the same on the final three sides of the die but for a fire ball ability. (Obviously this is an example and you could mix&match abilities and # shots a side gives assuming you go down this route)
Overall I enjoyed playing through this :)