This is your second game ever made?? This is great und much fun to play!
Because you asked for it, here my suggestions :)
- look into parallax scrolling! it would add so much to the graphics and without too much additional effort
- sometimes it's frustrating when you jump right into a snake pit because you didn't see it during the jump. You could zoom out with the camera whenever you jump high.
- allow the player to do small jumps (hit the keyboard only quickly) vs. large jumps (press and hold the keyboard)
But again its a great submission, addictive!