Thank you for playing the game.
The "lacking visitors" appeared because you need to unlock visitors at the reception for the posibility of any of them appearing in the dungeon. (the more types of visitors unlocked, the bigger chance of getting them in the dungeon).
If you interacted with the hearts after Activating the mirror, you would see the finding the target is not valid anymore, and you should just return to the entrance. I shall make it more explicit in the pause screen as well.
"-crouching lets you dodge every arrow"
by the design, it lets you go under arrows that shoot at certain hight, but you would still get hit by e.g. arrows shooting from ceiling. The thing with crouching is that it slows you down, but that can also be followed with a dash, and jump.
"-dashing in the air lets you skip pretty much anything, i never used the crates to jump on them"
yes, dashing is really good for quickly getting through many obstacles. The downside is the precision, and of course Mana. If you play with a timer, you might find it that jumping on crates is less optional in some situations, because you gain extra mana, and bonus time from them.
"-when you jump on a wall you can wall jump at some angles"
I assume you are not talking about the multi jump ability, which lets you jump in mid-air. I would like to know more details in where you experienced that.
"-crouching and jumping lets you jump double the height of a normal jump"
it's not exactly double, but yes getting a boost to your jump from crouch is intended. You can also bounce higher if you land on crates and mushrooms in a crouching position. Crouching also lets you to drop faster, so it is good for using it in vertical rooms when dropping down.
Thank you very much for all the feedback