Haha. I don't really have any art to put into the game, or the means to create it, unfortunately.
The rest system was actually not too bad, as its effect is fairly constrained to the puzzle set pieces. You can see how it's implemented if you dig into the source code I posted as a separate file.
As far as the energy and the puzzles in general, right now I'm in a place where I realized that each puzzle is giving me a big meaty chunk of stuff to write, which I spend more time on than the puzzles themselves, so there probably aren't going to be very many or very complicated. An interesting lesson from this game is that this particular type of puzzle doesn't lend itself well to building up towards large, complex designs in IF, if only because it would be quite difficult to keep up with the level of detail you'd want to see in an interactive fiction game.
Edit: I probably should also note that the resemblance to Hadean Lands isn't coincidental. I was looking for inspiration for more "system-like" puzzles, which are fairly rare in interactive fiction, so I re-played the game to help give me ideas for my design.