"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)."
Ah I see makes sense. I tried playing again, unlocked visitors and got a face in the mirror
"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."
Yeah that wasn't clear at all.
"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."
How do you get the timer? I just played 3 games in a row and I timed out in the third one, I never noticed the timer if there was one, maybe put it in the center of the screen? also what is the leftmost bar? the second one seems to be mana recharging. And yes forget the thing about walljump, I didn't understand the mana thing before but after reading your comment I got it