Nice game !
The gameplay is quite easy to understand and delve into & there's a nice little amount of strategy into it. The tutorial is really efficient and well made. The visuals looks really neat and the sfx fits well. the music doesn't really convey the mood of the game but it sounds fine anyway.
in terms of feedbacks, there's not much to say. It's pretty well rounded.
As mentionned by others bellow, the sword feels really weak and I ended up not really using past a few levels. Compared to it the fire spell feels really powerfull (maybe limiting the fire range and proiding a way to upgrade the sword would help with balancing the game)
Some random loot/upgrade would really help in term of replayability.
All in all it's a really well rounded game. Great work :)