I'm sorry to say this, but this is not an example of a good point and click style game.
There are so many things wrong with it and I'll start with direction (as in where the player should go): There is little to no information on where the solution is on some of the puzzles and that's good in that it promotes exploration, but it's bad because it's not executed well in this game. The first locked box number puzzle is ridiculously easy to overlook and I only noticed the solution out of sheer luck; a simple fix could in the form of simply an acknowledgement that the numbers are even there (like "what could these numbers be?" or something).
Next is the objects required to solve some of the other puzzles, like the screwdriver for example. I eventually resorted to essentially cheating by spamming TAB to highlight clickable objects for me because I just couldn't see half of the stuff (either too small or didn't stand out).
The setting of the game didn't make a whole of sense to me. Am I trapped in a Church? A theatre? A dentists office? Don't get me wrong, some of the places fit together seamlessly and the whole setting is clear, but each section looked at individually just doesn't make sense to be with the other sections. Also the map was pretty useless considering it doesn't solve a puzzle or even have any points of interest.
Lastly is how necessary the walkthrough was and how it shouldn't have been. The piano puzzle required me to watch it because of how stupidly easy it was to overlook where the clue was hidden. And then I had to watch it again to find the last gem because there was no indication I had to go back to the room it was in. No text, no sound effect, nothing.
Anyway, I want to end on something positive and say that I'm in no way trying to discourage you from making more point and click games. I managed to complete the game eventually and give the dude the treasure so I could be free (although looking back, surely the rubies are worth more that treasure.)