Microsoft Windows

Unzip HeartOfDarkness-SDL-Windows.zip
Copy into it all datafiles (see README.md)
Launch Heart Of Darkness.exe
Enjoy

Google Android

Missing informations

Nintendo Switch

Create the directory /switch/hode
Copy into it all datafiles (see README), HeartOfDarkness-SDL-Switch.nro and hode.ini
Enjoy

PlayStation Vita

Install HeartOfDarkness-SDL-PSVITA.vpk using VitaShell
Copy all datafiles (see README.md) and hode.ini into ux0:data/hode
Enjoy