Really interesting game! Though my immediate reaction was "this mouse is too sensitive" - I had a hard time controlling the character and facing the way I wanted, sometimes just looking (then falling) straight down, especially after I got the dash and jump. I also found it odd to control the dash and jump with the mouse, which were the default settings... maybe because I clicked them? It said something about keybinds, but it didn't have any instructions for how to use that. It may have been as easy as "click a different button at the right time" or something, but some visual aids/instructions in-game would have been helpful when I got to that point. I did like how there were a lot of elements all in one big room, and I was so glad when I died and realized those tops (that I tried for too long to pick up) were save points.
All in all, good work here. It would be interesting to see how far you can take it if you continue tinkering after the jam!