Fun game! I couldn't figure out how to beat snakes without taking a hit, but it sounds like you are working on the issue with the attack. I was worried about the spikes, but it ended up being no problem to dodge them with proper timing. Same with the moving platforms, I was worried about getting thrown off when they changed direction, but they were very easy to land on and stay on.
The dash didn't seem useful for anything, was it intended for a particular task? It also had a problem with responding to input like the attack, so I didn't bother using it.
I found the wall climb and escaped the underground area. After that I just fell off the edge of the world on the right side. Does that mean I won? :)
Good luck expanding your game!