In case anyone is still struggling with completing the game, I made a full walkthrough to help you out:
The game itself is quite fun, however the gramophone puzzle isn't very intuitive.
Hopefully one day you guys come out with some more games! :D
Here's also a video in case you can't quite get it to work over Hamachi:
Once you do the steps in there, all you need is one player to host the game and the other to input the host's Hamachi IP. It should all work then :)