What I liked the most: Pixelart and the layout of the dungeon controls.
What I didn't like: Short music looping. I thought there would be a pretty redheaded girl to control in the game :P
I found two bugs. In the first fall of the phase with creatures that fly appear, in the fall, the player walked to the left, however, his sprite remained to the right. Pausing and starting his movement, he went to the right.
The second bug, I suspect is a problem I had with my game. On the springs, I couldn't get the character to reach height at all, I was stuck there. My game, for some strange reason, also got jump-heavy suddenly and only on my computer (even without any code changes). Did you use platform behavior?