I originally reviewed this shortly after playing it during the IF Competition, which was a mistake. The stress/strain of having limited time to play brought out a (bizarre) inability to even figure out the basic mechanism at play.
I've since re-played it: it is very, very clever, but far from impossible.
Don't spoil this one: most of the joy is in figuring out the mechanic and exploring it.
On top of the excellent puzzle mechanic, the writing is good, fun, and crisp.