There is a secret level in Inside the Backrooms that is said to be the most difficult and odd level in the game so far. But as usual with games, such levels are hidden behind secret unlock requirements.
To unlock this hidden level, players will have to use a computer in the Officerooms level. There will be a code that players can use to unlock the security door leading to the secret level.
Read below to see how to get into the mini-level in Inside the Backrooms!
How To Activate “Run For Your Life” Mini-Level – Inside The Backrooms

Once you are in the Officerooms, you can look for a computer you can interact with.
You can use this computer to open a blue door which leads into a pool. Crossing this pool leads to another area.

This room has a locked grate on the floor and pillars with letters and shapes on them. That locked grate is the security door that leads to the mini-level.
Take note of these drawings and look for a piece of paper nearby.

There will be a note that gives a clue on the code that you have to input in the computer to open the security door. With the example picture from before, the 2nd letter of the code is “L” while the 4th letter is “S”.
Be wary that the code may randomly generate for each player, so take note of the pattern and input it back at the computer. Upon inputting the correct code, you will get the notification “Security door open…”.
Now you can return to the security door, and jump into the mini-level!