Nice platforming mechanics! I loved the details with the rock throwing and idle animations! The backgrounds look great too for the map. At first, I wished there was a way to aim the rocks instead of just controlling their power, but the more I played, the more I appreciated the extra challenge of not being able to aim. Interesting mechanic with that one!
I will concur with the other comments that sound design is definitely a must here, and that the controls aren't quite ideal. Personally, my suggestion would be to switch running to right shift and attack to left arrow, but with a game that has so many different controls, I think everyone would have different preferences. It might be worth looking into how to make it so you can rebind the keys. That way everything can pick!
With gameplay, like I said, the platforming is great! Nice job with the level design. The only thing I had a slight combination of issues with the enemies. First off was the lack of health pick ups, the second was the lack of cool-down between enemy attacks, and third was the enemies tendency to spawn in the way without warning. On their own, these are all interesting aspects that could add to the challenge. But combined together, they made the levels feel a bit impossible. In particular, the combination of the spawning and the lack of cooldown would make it so I'd just be running, a snake would spawn right on top of me, and before I could even escape, it would drain all four of my health and I'd have to start over. But by tunning one or two of these issues, I think it'd help a lot and really add to the game!
Good job with this so far!
-Sasha