The game is really nice, but there a lot of issues. Here is my feedback:
When the platform looks like it should hold you and you fall off should at least not be located in level 1;
I really love the invisible platforms, but when you take damage you need to know how many life's you have left;
I had some issues with the graphics, zoom in on the screen more so you can see yourself better. Background needs to fill the entire level, and there needs to be a bigger jump buffer.
Overall I had a good time playing and really loved how it works, just needs more time...