Ecdysis is a compact bit of horror. Summarizing the plot too much would only ruin it, but it's worth knowing that this is one of several games based on snippets from H. P. Lovecraft's "Commonplace Book", and that the premise is a weird and disturbing one.
Ecdysis is fairly linear up until the late stages of the game. I found that the first release of the game had some awkward moments, but the later release is smoother and easier to play. Puzzles are mostly a matter of figuring out the one next thing you can do, and are not too hard -- but all the same this does make some good use of its interactivity. Worth a look.