A disaster.

This is a really clever idea you have, about the box and how different codes will get you different things.

Just a heads up: after you stab the reflection in the mirror, any time you go back in to look at the mirror, he still flashes there for a short time before disappearing. I don't know whether or not this bothers you, but I wanted you to be aware should you feel the need to fix it.

The first time I played it, everything was working fine. However, once I lost and clicked replay, I saw the mirror in the box when I punched in the right code, but when I went to grab it this time, it disappeared from the box as if I had grabbed it, but didn't appear in my inventory.

Gonna hafta give you a low rating here, not only because of the obscure steps to complete that only sorta make sense in hindsight (had to tab to get through some things), but the screamer at the end. Incomplete walkthrough:

1: Notice code 1869 on wall, then click either side of the room.
2: Notice mark at top of this wall, showing that second code is 6981.
3: Go back to main room, click on box in center of the room and enter both codes, picking up the code box from 1869, and the mirror from 6981.
4: Drag the mirror to one of the walls, which places it onto the wall.
5: Click on mirror, watch creepy old man, notice the code 5315 he spells with his hand.
6: Go back to main room, click on box in center again and enter the code for a knife.
7: Back to the mirror now, and press the small (invisible unless you use tab) area on the lower right of the mirror to go to a sub-area.
8: Notice that the pattern corresponds to the code box, and enter it (form the wave for the top part, the bottom part is the stems/support parts for the knobs, and then just cycle through all 4 positions for 1 of the middle knobs before turning the other one position). Click the code box's latch to open it and get the piece of paper inside.
9 through ??: Unknown, I would assume the piece of paper comes into play for getting the second mirror but I had to use tab and enter at this point to get it.
A: Kill the creepy old man in the mirror with the knife, place the second mirror opposite the first one and start hitting the right arrow which shows up.
B: Eventually reach a room which has the code 10 left, 7 right, 13 left, 14 right on the wall.
C: Follow the code using the arrows which switch rooms, then enter 5 invalid codes into the box in the center of the room (this would normally give you a game over before now by letting the demon through the doorway behind you all this time, but he's gone by now).
D: Click at the bottom of the screen in the main room to go to the doorway, whose demon is now missing and the candles are completely out. Click to continue.
E: Keep on going down the hole, down the stairs and to the box (use tab if you can't figure out where to click). Click the lid and then turn down your volume.
F: Click inside the box and endure the screamer and weird imagery. You've escaped.

Hello here I have the normal code that must give my box after I made the code which has to give my mirroire is after the code of the gentleman miroire gives me gives me a knife block it.

Normally in these games they have a small clue or hint on how to solve these puzzles where i felt like you kinda just were like " hey I got some knobs here, figure em out". You should give people an idea of what their working tword without giving them the answer. Soundtrack was creepy but it was just the same short audio loop got boring and repetitive. Also what atmosphere are you going for in this game? If it's creepy that super friendly demon ruined it for you... You should try highlighting the things you can interact with when you scroll over them as it can get a little frustrating finding things on screen.
It's an admirable first try but you can tell it's your first try.