In the game, there are many references to ancient Egypt, which shall be hereby listed and elaborated on.
Sarcophagus[]
Apart from the 
Painting at the end of the corridor leading to the Study, the actual room contains a large 
Sarcophagus, which appears to serve as some sort of travelling device, allowing us to enter the surrealistic abode of Hawk's Prison. Initially locked, the Egyptian receptacle can be opened by placing seven 
Serpent Statuettes on the circular indentations in front of it.
Anubis[]
Before freeing Hawk from his prison beyond the Sarcophagus, the ethereal staircase leading up to the tower gate to St. Michael's and Charles Randall's Vicarage will be blocked by a peculiar, golden portal. The name for the corresponding texture of this door is called ANUBDOOR.bmp which we could read as an abbreviated reference to Anubis, the ancient Egyptian deity commonly associated with mummification and afterlife.
Scanning the texture files, I've found that there some other files, pertaining to this specific area beyond the Sarcophagus, that bear a reference to Anubis in them:
- BIGHAND2.hand on anubis clock.BMP (potentially referring to the large floor clock)
- SLADD1.ladder to anub gate.bmp (referring to the ladder which we descend by entering the Sarcophagus)
Rebecca's Pendant[]
The design of the magically imbued amulet that Rebecca usually carries around her neck is faintly reminiscent of the Egyptian Eye of Horus. There's a green gem in the centre of Rebecca's pendant which could be a fragment of the Soulstone. This would explain why she doesn't need a shard of green crystal in Temple of the Morning Star.
Gnarl's Domain[]
The design of the hall in which we make the Gnarl's acquaintance bears many references to ancient Egyptian culture, mirroring some of its well-known architectural monuments such as pyramids and the Sphinx of Gizeh.
Masks[]
The Egyptian Masks that we receive from passing the Gnarl's test in time serve as some sort of travelling and teleporting device, allowing us to access the Tower and the four Realms, Heled, Raquia, Arqua and Sheol. Their design appears to be inspired by the headgear of ancient Egyptian pharaos, the so-called Nemes.