#General
You can compile the source simply by opening *.lpi in Lazarus IDE (version 1.9 and above) and pushing F9 to compile&run.
#Requirements
This version requires at least 6.5 Castle Game Engine version to compile (at least 08.04.2018 GIT version). You can download it here https://github.com/castle-engine/castle-engine and follow installation instructions here http://castle-engine.sourceforge.net/tutorial_install.php FreePascal compiler at least version 3.1.1 is required. I recommend using FPC+Lazarus trunk (SVN) version (best after 2018-02-17) due to better Generics.Collections support in recent CodeTools patches. You can easily install latest Lazarus+FPC+cross-compilation tools with fpcupdeluxe. See https://github.com/castle-engine/castle-engine/wiki/fpcupdeluxe for more info.
##Linux
You need both normal and development versions of the libraries required for Castle Game Engine to run properly. These are (Debian/Ubuntu package reference): libopenal1 libopenal-dev libpng16-16 libpng-dev zlib1g zlib1g-dev libvorbis0a libvorbis-dev libfreetype6 libfreetype6-dev libgtkglext1 libgtkglext1-dev You will also need dev version of OpenGL drivers for your video card. Usually it is libgl1-mesa-dev. Note: the libraries versions may change and not every library has a meta-package.
##Windows
Specific DLL libraries (32 bit / 64 bit) are required in case of Windows. These may be downloaded here: http://castle-engine.sourceforge.net/engine.php. The DLLs must be placed in the exe folder.
#Command-line compilation
You can compile the game without Lazarus IDE using Castle Game Engine build-tool https://github.com/castle-engine/castle-engine/wiki/Build-Tool.