The game itself is decent fun to play... I got upto level three in the first few minutes so the difficulty was fine for me. There were couple of things I feel could be improved.
1. The jumping over the enemies is a bit weird. I sometimes hit them while I'm doing the jumo which kills them, and sometimes jumping gives me a much bigger boost. Sometimes after jumping on them I can jump in the air as well! I find that a little confusing but maybe its just me.
2. You could jazz up the visual effects a bit... especially the dying animations. That'll make the game seem more impressive!
Great tip about the ladder. I was in two minds about the timing of that. My best is level 6 at the moment so it does take a bit of practice to get the timings right on the jump. Thanks for the feedback.