The reference information is nice to have, but it's a bit clunky. At the start of the game. I had no idea what any of the text boxes on that page meant. I figured it out by checking it constantly during the tutorial to match what I was seeing in the tutorial levels to information on that page, but it wasn't as obvious as it could have been. I think it would have been good to have that information as a text element in the level so the player can read it while they're doing the thing that the text explains. That as opposed to needing to click through two menus in order to find that information.
Having both the number and the durability as separate concepts threw me a little at first, especially since the number of conversions until breaking is not obvious from the sprite. (Unless you go back to the reference info and directly compare, which is clunky.) I don't think the durability mechanic is bad, (it's important for a lot of the puzzles) I just think it could be represented better to the player.
There is nothing in the tutorial that mentions that you can pull elements or requires that you do it to pass the level. I only figured level 1 because I remember seeing something about a pull mechanic when glancing over the game description. If it weren't for me remembering that, I probably would have been at that level for a while not knowing an important key to the puzzle.
Undo could use a hotkey, as well as a press-and-hold function to skip a lot of moves really fast.
All that clunkiness asside, the game has some really nice mechanics and you used them well in the five puzzles. I particularly liked levels 2, 4, and 5. Every time I thought I had it, there was just some little complication that got in the way I had to work around. 5 was really tough. I had to rethink the problem several times until I found a plan that worked. As a hard puzzle game lover, this really hit the spot! Great job!