Assuming you are familiar with the Getting Started with Game Code guide and the basic concept behind GameZero, select [GameZero] Profile, x64 from the configuration settings to compile CryGameZero.dll
Loading procedure
Sandbox/Launcher reads from system.cfg which game folder has to be loaded - sys_game_folder=GameZero
game.cfg inside game folder specifies which game DLL has to be loaded - sys_dll_game = CryGameZero
DLL Loading pipeline is triggered as illustrated below