Thank you! :) There are a lot of things I'd like the player to discover. Opening doors is one of them. You need to pay attention to the dialogue because not explicitly showing what you can do is intentional. To make a good surprise when you discover it. I spent a day thinking about implementing some marks on doors or not.
Let me know which parts of the game you feel a bit lost, and I'll make it somehow clear without holding the player's hand. :)