This is actually quite fun!
I love that you gain momentum upwards from ramps when you jump. Awesome mechanic! Could be used later on in the game for some tricky jumping puzzles maybe? Anyway, loved the art style of the intro, but I have to agree with Boyh in regards to the contrast between the text and the background it sits on. You should make the background of the text box less opaque and make it contrast considerably from the text.
Great fun! Can't wait to see the finished product!
In the intro the text and backgrounds are too similar making reading difficult - introduce more contrast. The levels are quite barren. Other than that it looks promising.