The Deluxe Edition includes the base game plus several digital extras found on GOG.com and PCGamingWiki : : An exclusive in-game weapon skin.
To run this version, your PC generally requires the following minimum specs according to Steam and System Requirements Lab : File: Serious.Sam.4.Deluxe.Edition.v1.08.zip ...
: Enabled official integration for sharing and downloading community-made mods. The Deluxe Edition includes the base game plus