Hi.
Concerning the difficulty, in normal mode, I didn't manage to finish the first level. The difficulty seems to me correct but I didn't find a place to get water to restore energy. (But I'm not a good player either)
What bothers me a little is to have to press the E key to get the coins, I think it would be better if you could get them by touching them.
I don't know if it's because of my headphones, but the music was a bit noisy sometimes.
For the rest the graphics are well done, the atmosphere is very well done too, so it's a very good game.