Thanks you. This has been very useful. I reached two times the last screen, but unfortunately I still haven't beaten the game.
I've been victim of a painful bug a few times : the game can freeze when you are on the bridge just before entering the boss' castle. You just can't advance, like if there was an invisible wall. It's particularly frustrating, like this other time when I reached this bridge with three lifes left (I had never done so perfectly before), just to be blocked by this fucking bug.