I'm glad you liked the subtle hints in the level design. It can be hard to balance that kind of thing so it's good to know I did it well.
The little steps with odd inputs is completly intended, and there's even a level designed around that concept, however there is another level that can be exploited which I had to patch for post-jam. It's something I want in the game, because it works as a nice tool, but I have to really be careful with it (and I wasn't quite careful enough with the jam version).
I also agree that the concept as it stands can't be stretched that far beyond the 10 levels, but hopefully the new level mechanics I've envisioned will vary it up if I implement them well.
I'm really happy you liked it, and thanks for playing!