Many puzzles in Beyond the Long Night revolve around setting puzzle tiles to a specific symbol by shooting them. Very often you determine what symbol a tile should be set to by finding a reference to it in the background of the screen you are on.

This guide contains visual reference for the puzzle block symbols to help more easily identify the hints in the background.

I have also added information on solving the final puzzles in the run in the last two sections (marked with spoiler tags).

This section covers the secret tiles found later in the game.
_____________________

______________________

If you haven't found the Great Wall and don't want spoilers, skip this section!

Basic description:
Eventually, with enough story progress, you will discover the Great Wall in the Hope's Peak zone.

The screen has three secret puzzle blocks & three matching pedestals. You can shoot the blocks to change the symbol on the front of them. You can also pick the blocks up to drop them on the pedestals.



Finding the solution:
In order to open the Great Wall, you first have to reveal the correct symbols for the blocks.
Hint 1: You must find the source of the Storm.
Hint 2: You must talk to Sara at the source of the Storm. This can help you survive long enough in the rooms that will reveal the solution. She may also have some hints on where to find the solution.
Hint 3: Archie may have some good ideas on where to find the solution.

Solution:
Wait in the Faces of Stone obelisk rooms for the Storm to spread to the room. This will destroy the obelisk and reveal one of the three symbols for the blocks in the Great Wall room. For the six Faces of Stone obelisks in each run, two obelisks will contain the first symbol, two will contain the second symbol, and the two others will contain the third symbol. It is random which obelisks will contain which symbol, so it may take multiple runs to find all three symbols. Once you have found the three symbols, the will be added to your journal and you can then use them, in order, to open the Great Wall. Shoot the three blocks in the gate room to match the symbols in your journal, then pick them up and place them in order on the pedestals in the Great Wall room.

This section contains information on solving the Invisible Gate puzzle at the end of the game. If you want to avoid spoilers, skip this section!

Basic description:
The final puzzle to reach the true ending of the game involves the Invisible Gate in the Sanctuary zone. Look for a single open room with one platform in the middle that is 10 blocks wide.



Revealing the Invisible Gate:
In order to reveal the Invisible Gate, enter the room mentioned above, then use the Ear Horn that you can obtain or buy from Uumpa.

The room has eight hidden puzzle blocks next to the blocks marked with the secret puzzle blocks 1-8.



Finding the solution:
In order to open the gate, you must set the puzzle tiles next to each secret number tile to the correct symbol.
Hint 1: You have to complete the Great Wall puzzle first!
Hint 2: Solving the Great Wall puzzle will open a portal to the Dream. The solution is hidden somewhere inside.
Hint 3: To traverse the Dream, you must find the correct exits for each screen. Follow your ears to find the correct exit.
Hint 4: Use the Ear Horn item you get from Uumpa to find the correct exit on each screen.
If you haven't found it before now, you may be able to blindly stumble through the exits until you find a sleeping Uumpa -- they will sell you inventory, including the Ear Horn.

Solution:
Solve the Great Wall puzzle to open the portal to the Dream. Use the Ear Horn to find the correct exit for each screen (denoted by a circle after using the Ear Horn). At the very end of the Dream, you will find a dream version of the Invisible Gate, which reveals the solution for the Invisible Gate puzzle. Now travel to the Invisible Gate room in Sanctuary, and set each of the corresponding puzzle tiles to the correct symbol. This will open the Invisible Gate.

(I am not sure if the solution is different between different players' installs of BtLN, but the solutions has not changed for me between runs)

If you have any additional information, such as the names of the symbols, missing symbols, or any words / numbers that they represent, please comment and I will update the guide!