Thanks for feedback. About monetisation:
1. On this site, I did not monetize. Just try this site, and think about it.
2. On mobiles (app store/googleplay) from the third episode (according to the plot) it is necessary to pay the full version of the game. But initially I did otherwise. There were many pitfalls in the game, in which the player often came across, after which he had to watch the advertisement. From this approach, I decided to refuse, that would not spoil the impression of the game itself and not complicate the game.