The Mysteries of Sphinx (also known as beta content) were parts from the Sphinx and the Cursed Mummy that were cut out.
Sphinx's Winged Lion Form Edit
Originally, Sphinx would've had the ability to transform into a winged lion and take to the sky at certain points of the game. In this form, Sphinx would have took part in aerial combat and chases. The second of the trailer of the game at http://gamespot.com shows Sphinx in this form flying high over Uruk and through a valley of lava. Although this idea must have been scrapped quite early on, the Bat Mummy probably replaced it.
Thebes is marked as a location (orange text) in the description on one of the Abydos Jewels, possibly hinting as to its inclusion in the nonexistent sequel. Of course, this could simply be in the game's habit of marking all locations orange.
Skeletal Armadillo Edit
The description for the Fire Armadillo mentions a third type of Armadillo called the "Skeleton Armadillo", which uses the standard spin and charge attack, but has no fire or electricity. It is possible that it was cut from the game, or, it was just never in it.
Some early screenshots and the bonus "Making of Sphinx" video in the game show that the Geb Queen's Palace was originally different than the one seen in the final game. It seems that the Gebs would have assisted her during the boss battle instead of Skull Swordsmen. In the final game, the Gebs are only ever seen in a cutscene and in the Abydos Museum. It resembled the current palace, but had a green tint instead of it's current orange
Early screenshots show Sakkara, an entire region that was cut from the game. An early preview of the game on IGN.com said "There are the jungles, swamps and lakes of Sakkara". The music track which plays in Heliopolis is named "Sakara" on Eurocom's website although it seems that most of the names have been mixed up (as the Luxor Palace tune is misnamed "Aby Main"). A beta item named "Sakkara Amulet" would have presumably teleported Sphinx to a Portal God located here.
"#define HT_Objective_Sak_Refuge_AcceptMission 0x420000f9
- define HT_Objective_Sak_WaterDirected 0x420000fa
- define HT_Objective_Sak_GotMagicWater 0x420000fb
- define HT_Objective_Sak_SeenFall 0x420000fc
- define HT_Objective_Sak_Refuge_ElderTentOpen 0x420000fd
- define HT_Objective_Sak_Refuge_GrowPlant1 0x420000fe
- define HT_Objective_Sak_Refuge_AcidBlockDone 0x420000ff"
The code above is extracted from the 749th file in FILELIST.000 of the sphinx retail disk, it shows that magic water was to appear at some point in this level.
(Sakkara is named after a large Egyptian burial ground named Saqqara, noted primarily for hosting the first Egyptian step pyramid that belong to Pharaoh Djoser.)
The underwater city of Akaria was another region which didn't make it to the final game. It's seen many times during the bonus video contained in the game and there are many more screenshots of this region on the web. A beta item named "Akaria Amulet" would have presumably teleported Sphinx to a Portal God located here.
Uruk Valley Edit
Little is known about the Uruk Valley, it's existence is evidenced by the fact that an amulet which still resides in the game's coding and can be equipped, is called the "Uruk Valley Amulet" - using this on a Portal God will cause the game to stall, disabling the player from doing anything whatsoever until the game is restarted.
Castle of Uruk Edit
While being a playable level by both the mummy, and in the end, Sphinx, a fourth amulet, named "Castle of Uruk Amulet" suggested that it would have been possible to frequent the level as a Portal God may have existed there at one time, this suggests that some parts of the Castle of Uruk were scrapped.
- Akaria Amulet - An amulet in the game which was once able to grant the player access to Akaria, now causes the game to stall when loading the level.
- Cage Key - The cage key's use was never defined, but it is believed that it may have been used to free Khensu.
- Great Wall Keys - The Great Wall keys were thought to have been collected by Tutankhamen in order to grant Sphinx access into the Great Wall of Heliopolis. The item was probably replaced by the Atum idol, which dispelled a magical barrier separating the Cursed Palace area from Heliopolis Point.
- Hour Glass - The purpose of the hour glass is currently unknown.
- Ishka's Ring - The purpose of Ishka's Ring is unknown, but it is known that it belonged to the beta boss, Ishka.
- King's Proclamation - The purpose of the King's Proclamation is currently unknown.
- Ledge Door Key - The purpose of the Ledge Door Key is currently unknown.
- Old Cellar Key - The purpose of the Old Cellar Key is currently unknown.
- Page From Set's Diary - The purpose of the Page From Set's Diary is currently unknown.
- Sakkara Amulet - Another amulet which would've transported Sphinx to Sakkara, suffered the same fate as the above.
- Talisman of Honour - The purpose of the Talisman of Honour is currently unknown.
- Trophies - The purpose of the Trophies are currently unknown.
- Vial of Geb Acid - The purpose of the Vial of Geb Acid is currently unknown.