Unfortunately, attempting to guess the encoding of a phrase is not possible. Even after looking at the source code, inputting the correct phrase would only reveal the first letter.
I am convinced that there is quite a bit more to this game than just guessing a sentence (from what I could gather from the source code), but it just wasn't finished in time to submit to the jam in full. Some big chunks of the code are never called. Unfortunately as it stands it is broken.
