I have just finished this with a friend, and what can I say, it is fun, play it!
The idea is both novel and cosy, a way to enjoy IF in two, without requiring servers or an internet connection (you could play it both in the same room, on different machines)!
The story is there but not prominent, some puzzles were a bit too hard for me but the hint system is superb (and the hint mechanic too, you have to ask your friend!), so again warm feelings.
I hope the author keeps making games!
SPOILERS AHEAD
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My friend had problems because he typed `GO UPSTAIRS` and `CLIMB UPSTAIRS` but the commands were not recognised.
I managed to solve each puzzle on my own after reading the hints bar from BEFORE.