Keep a notebook
There are a lot of back-references in later levels, which are tedious if you havent kept thorough notes. Most of the puzzles are fun, but some are not that logical.
The sound-based puzzles use extremely high pitched sounds which are very hard to hear. If you have any hearing loss, you wont be able to get those clues. Also those are annoying to listen to, like a cricket.
Section 1 was fun, 2 was a mix, and 3 was frustrating. Like I said, keep notes.
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