Spoilers

For all of you who are having a hard time, here's a video showing how to complete some puzzles in the first chapter:

https://www.youtube.com/watch?v=HHfwI9TXkeU

The video shows somewhat older version of the game, so some puzzles are changed and the order is not the same. Still, it can give you clues or ideas if you get stuck somewhere.

I considered about updating it with a recent version, but maybe it's more of a challenge like this, so I won't. From chapter 2 onward, you are on your own :)