Here is the full list of all 32 Dex achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Sold all the antiques to Hank
Didn't leave anyone behind
Opened the safe on the Eclipse
Acquired the laser gun
Exposed Crash's identity to the world
Met the new BiofarmTech receptionist
Drank more than 10 Energo Colas
Successfully used the Convince option in a dialog
Performed a headshot
Performed 20 Takedowns in a single playthrough
Had a taste of all the 'professionals'
Found Soto
Got crushed by an elevator
Completed the game
Met the original
Reunited ill-fated lovers
Reached level 15
Showed THE Armagear hacker who's boss
Rescued Shen
Bested a war machine
Forced Mitchell to confront his past
Opened Ellie's eyes
Installed 7 implants
Upgraded a software to its maximum level
Opened the safe in the Aphrodite
Reached level 10
Maximized a Major skill to level 6
Neutralized the TruBody gang
Defeated an old acquaintance for the second time
Helped an old man off the street
Picked 10 locks
Reached level 5