Glad you liked the art! Kayla put a lot of work into it, and it turned out awesome.
About the gameplay, sad you didn't like it. But the thing about enemy speeds probably isn't the reason since they vary pretty notably. For example the crow is ~3x faster than the bear.
If we continue working on the game we might add new behaviors to enemies and spells which could add variety.
About the theme, we took a risk by not going full on water, we thought it'd be creative and refreshing from other games. Still, we referenced water as aqua too, like Grandmama mentioning the aqua spell(water spell '3') as the strongest spell witches use. I personally think the announcement video having water in it shouldn't limit the interpretations of the theme, it's just there to announce it.