I revisited this game after five years. This time I was struck by the enjoyability of playing around with the transformation machines. Nothing is more fun than making an enormous wooden dress and destroying it, or making a spongy key. The total number of possible items you can make it immense.
Emily Short describes on her website that this game was developed in part because she was trying to implement different textures, sizes, etc. to make an extremely customizable game. Thus, like with many of her games, this game tries to push the boundaries of what IF can do, with a story wrapped up around it after the fact.
Other examples of this "new implementation or gameplay technique wrapped up in a story" are Counterfeit Monkey and Galatea. However, for me, story is my first concern with interactive fiction. That's why I love the intricate details of Curses!, Anchorhead, Worlds Apart, Theatre, etc. So this leads to an interesting effect when I play Short's "implementation" games; I have a blast at the time, and then generally forget the game afterwards. Metamorphoses is such a game; it's fun as a tool, but not very memorable as a story. The same is true of "Dreamhold" by Plotkin, which was designed as a tutorial.
As a final note, I love Short's story-heavy games like Glass. Remembering the "smell of blood" ending creeps me out...