Spikes are too hard to see, stones that falls from outside of screen are not fun.
I found the waterfalls a bit annoying, would suggest reducing their effects but maybe it is just me.
Game window is very small in the beginning and it is kinda hard to make it full screen without being able to see your mouse.
Other than these problems, it was fun! I will be looking forward for you to add more content.
One bug I noticed: sometimes your character sticks to walls. I don't think this is intentional, right?