Glad you enjoyed the game, and sorry to hear that the difficulty curve causes problems. I did try to make the game fair, and overall I'm happy with the design. That said, I know that the "tree" causes problems for some people, and I had to balance the difficulty of that puzzle against the pleasure of figuring it out. It's still not perfect, and so, the base64 hints can help out without changing the puzzle design.
I also built the "rollback" feature into Adventuron primarily driven by the wish to use "death as a learning mechanic". I do think that in-game death is kind of fun in adventure games, so long as you remove the penalty of losing progress, and so long as you don't make the game unwinnable. TWO never lets you put the game unwinnable (to the best of my knowledge).