You know what, we should try it! I will add a crouching section and see if people like it. I will add an option to switch it off.
As for the challenge, please give me some time ;) Earlier I wanted to add a very unique puzzle to each section but the game evolved into more open world. Though, I still want to add some puzzles and challenges. Keys are something pretty standard but I think that there is always some place to have them in game.