Here is the full list of all 35 Cliffhanger: Challenger of Tomorrow achievements.
Beat Charles Lindbergh’s transatlantic record
Escape Franklin’s Isle
Make a fortune gambling at Monte Carlo
Drive in the Grand Prix
Party with Noël Coward, the Aga Khan, and Wallis Simpson
Survive a walk through the Garden of Forking Paths
Recruit Jacob ben David
Recruit Doctor Devi Naryan
Recruit Hedy Kiesler
Recruit 44
Recruit Princess Sonia
Recruit Liou Hann
Recruit Ali Murtaza
Recruit Le Chat Noir
Kill Hitler
Track Arnold Rothstein down
Beard HPB in her lair
Meet with Hassan-i Sabbah
Find le Spectre
Face off against the Golden Bat
Overthrow Colonel Klaw
Forge an alliance between Communists and monarchists
Find out the truth about Arkaris’s art collection
Learn the truth about Ah Ken
Kill Renfrew
Permanently acquire Project Colossus
Harness the power of dreams
Decisively defeat the Doomsday Legion
Overthrow the Four Empires
Conquer the criminal underworld
Take down the Syndicate
Protect free speech
Ensure the future of scientific progress
Restore the world’s knowledge of Atlantis
Become rich