Add the following lines to the file grimrock.cfg in the game data folder:
consoleKey = 192
This sets ~ to open the console.
The scripting reference can be found here.
You used to be able to place a handy Debugging Toolkit into the folder containing grimrock.exe and then access it in the console by typing dofile('debug.lua') (a list of commands was available within the file itself). However the dofile command is no longer available, likely to prevent arbitrary code execution from malicious mods.
Enabling Vsync may fix some issues, such as periodic freezing. This is because the game does not have a frame rate limiter, therefore it will tax the graphics card very heavily. Vsync forces a frame rate cap.
A known issue regarding certain graphics card drivers. Resetting the graphics driver to default values from the control panel can fix this issue. This issue, at least on AMD cards, seems to be caused by forcing anti-aliasing via the control panel. Disabling it should fix the issue. Morphological Filtering (MLAA) seems functional as an alternative, but it can make small text and objects blurry.
Disabling mouse pointer trails fixes this issue.
Error message: D3DError - D3DXCompileShader failed: ERROR_BAD_EXE_FORMAT
D3DError - D3DXCompileShader failed: ERROR_BAD_EXE_FORMAT
A solution involves modifying a new DirectX installer.
Download the latest DXSsetup.exe from Microsoft.
Extract the DXSetup.exe to a folder.
Enter these subfolders:
32 bit folder - Windows\SysWOW64
64 bit folder - Windows\System32
Delete these files:
After doing this, rerun the DXSetup.exe from the original downloaded archive above.
This is possible using a utility called Swiftshader, which offloads shader processing onto the CPU. However, this comes at a heavy performance price.