I like the variety and differences between the enemies. I do think It would be better if the game had less visual styles.  with the large pixels of the protagonist, the blocks of color in the spears, and the larger pixel count in the frog, it just feels a little overwhelming.

Nice idea on the theme! I would add a bit to the others comments, add controls on how to play in the game or in game page would be quite useful, i had tried to press different buttons in hope that some spell will be used, but nothing happened, and then i saw your comment with controls.

As the other comments have said, more feedback for landing hits vs taking damage would be a big improvement, but I found myself coming back to this again and again after dying because I wanted to see what the power-ups and boss were! Great entry!

Hey guys, this is a game about killing a bunch of creatures and then receiving a power up to kill the boss!! (That's the butterfly effect)! WASD to move and mousebutton 1 to attack!!