If you don't see anything but a black screen when you start the game, you can follow this steps:

1. The most basic thing is to update the drivers of your graphics card, just to make sure.

2. Try removing this file:
(The filename may be a bit different, but not significantly.)

3. Try starting the game in DX11 mode. To do so, go to the game's properties and then switch the launch option.

You should try switching to the DX11 mode. An older version of DirectX uses simplified lightning and the difference in how the game looks is not significant.
The process of switching to DX11 is explained in the previous section.

There is a backup option present in the game that allows you to restore the rooms should they be removed from the game for any reason. You can find them by following the path:
Find the rooms you need, copy them to the folder:
And restart the game.

Steam Cloud is currently loading files incorrectly for this game, and your progress may not be displayed on the new device. Even if it's running the same operating system.
So you need to move your files manually. To do this, you need to copy your Saved folder and move to your new device.*
Don't forget to change the Username to your own. if you still can't find the folder, you can try to make a search using this:
*Steam Cloud may try to restore the save file to empty, and if it does, i recommend you to disable it.

The game doesn't have this option yet, but it's pretty easy to reset the progress yourself. To do this, you need to delete the file* located at:
*Keep in mind that Steam Cloud may try to recover it. If it does, you should try to disable it temporarily.

The game doesn't actually have a co-op mode option yet, but you can still build your room with friends or family who have the game in their library.
You need to open it via the Locate button in the game, it will point to the room you need.

Or, if your game is closed, you can find your rooms here:
And restart the game.

The names of the rooms will look like a set of random numbers and letters. Copy it and send it to a friend.

They should click on the Locate button in their game or follow the same file path, upload a .room file there and restart the game. After restarting, the room will appear in their list and they will be able to enter it and play.

I don't use this keyboard myself, but I've seen people request the option to change controls. While there is no such feature in the game, you may find this guide useful.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2771013430

At the time of writing the guide, all problem solution methods are working, but they may become obsolete in the future with the release of new updates. Perhaps the guide will be updated in the future.

If you notice that something is not working properly, you can contact the developers.

Thanks to the game developer, Alex, for provided information, and to Maxkoroch for editing the guide.

Thanks for reading!