I have downloaded your demo game. Looks very interesting.
I can figure out how to solve the puzzle.
I have read the other comments but I still can't figure how to solve it.
If it can help, the puzzle is an anagram. Perhaps I should add that as a mention somewhere to make it clearer.
I finally got it solved by going to an online anagram solver.
Maybe you should make the 1st puzzle in the game a little easier.
Some people might be discouraged from trying to solve it.
Just a thought
I will eventually update the demo with some more stuff in it, and the puzzle will most likely be slightly modified further. From testing with someone who plays a lot of puzzle games, this seemed decent difficulty to start things off.