It is hard indeed! I might tune it down a bit... but as you progress you get to add extra health up to 8, so it gets slightly easier.
I worked hard on the navigation system so I am really encouraged by your comment.
It's always a challenge to tell the player about the gameplay elements without words! Like that health power up, I gave it a different color but I will think about adding a clue... like at first, the skeletons were dropping balls of energy that were looking alike the health power-up... maybe bring back that.
So thanks a lot! I'm glad you enjoyed it :)