Here you can download The Ground Gives Way (v2.3) for Windows. Just unzip the archive and play. Be sure to read readme.txt for instructions. You can find the changelog compared to previous versions right here (contains very minor spoilers).
Windows 10/8/7/Vista:The Ground Gives Way v2.3
Windows XP SP3:The Ground Gives Way v2.3 (XP)
TGGW is currently Windows only, but has been reported to work on some Linux and OS X setups. See the FAQ for instructions. If you use Linux, the quickest way may be to use Pilcrow182’s launcher. You can download the launcher here.
If you find the game very difficult, there are some hints here (some of these are not really up to date with the latest release). There is also an (outdated) manual and a reference document of the game.
Does the Game Crash when you start it?
If the game crashes upon starting it, it is most likely because it displays the window in a font that is too big for your desktop. You can solve this by creating a shortcut to the game (right-click and select “create shortcut”), on the shortcut you can then adjust the font size to a smaller one by right-clicking the shortcut, select “properties” and then select the “font” tab and do your adjustments.
Thanks to TyreForHyre for this workaround!