Here is the full list of all 34 Sphinx and the Cursed Mummy achievements.
Find the Blade of Osiris
Find the Shield of Osiris
Find the blowpipe
Find the Hands of Amun
Find the Wings of Ibis
Obtain a zip line handle
Try to stay fashionable around palace
Complete the Heliopolis obstacle course in 77 seconds or less
Beat your best time in the Heliopolis obstacle course
Some of the best things in life are hidden in plain sight
Make the Riverside Farm habitable again
Uncover all the Atun Discs in Heliopolis
Find all the trinkets under the rich farm soil
Complete the first chapter
Complete the second chapter
Complete the third chapter
Complete the fourth chapter
Fulfill the Ancient Prophecy of Ra
Return all the Abydos Jewels to their rightful place
Complete the Abydos Museum's Natural History collection
Given by the Abydos Museum for collecting 30 monsters
Given by the Abydos Museum for collecting 20 monsters
Given by the Abydos Museum for collecting 10 monsters
Match each pair of items behind the doors to win this game
Awarded only to those who manage to beat the gauntlet
Test your skills in the mystical game of sequences
Prove your mastery of the Blowpipe
Complete the Heliopolis swimming course
Equip the Dark Stone of Invisibility
Complete the Heliopolis athletics course in 69 seconds or less
Share your feelings with your fellow apprentice
Some shortcuts will bring unexpected consequences
Increase your health to a grand total of 12 Gold Ankhs
Obtain all the precious Onyx Scarabs in the Castle of Uruk