Awesome job :D Nice music, Such a fun way of utilizing the mouse for casting spells!
Mechanics:
Spells
The wand is very fun to use, reminds me of fruit ninja where you slize fruits with your finger.
Perhaps if you fight fire enemies and projectiles the water should remove the projectile in its entirety as it seems too much to extinguish and swap wands to destroy singular projectiles. But it is fun that there is a mechanic to douse water on those and yourself and not only on the enemies.
On the enemies themselves I really don't mind using two different spells to defeat them.
Dash
The dash mechanics looks and feel pretty good, its fun moving fast and you are inclined to go fast when there's nothing around.
This does however end up having you fly into enemies, projectiles or other hazards very easily as you enter new areas. Especially since you are moving towards the edge of the screen while dashing.
Which then makes the optimal strategy on the first playthrough to not use dash at all, especially since checkpoints are not that common. While dash is a nice addition on repetitive playthroughs.
Perhaps if the camera was in front of the player while dashing we could see where hazards were. Or if we were more zoomed out or the dash was slightly shorter.
The camera would be nice in front of the the player in the direction you are moving when going slow as well, it is too easy to run into something when the camera lags behind.
Sounds
Love the music! It's a nice tune.
Sound effects have not been added yet? Things like casting the spell and hitting an enemy could help drastically with gameplay feel and would be a very short implementation. I.e. you already know when enemies take damage so just trigger a hurt sound when it happens. This also creates clarity for the player when you damage things.
Content
How did you do so much for a game jam?? I don't know how you were able to get it all done but great job :)
Difficulty:
I don't think the game is too hard. But I think the visibility is too bad and that makes the game hard. Keep the difficulty, zoom out or give better visibility somehow.
8/10
Check out my submission if you like as well, it is much much smaller than your project =(^_^)=