Here is the full list of all 54 Lennas Inception achievements.
Beat the "Daily Seed" challenge
Beat the "All Dungeons" challenge
Beat the "I AM ERROR" challenge
Get the "Catastrophe" ending
Get the "Sacrifice" ending
Max out your heart meter
Get one of every item
Master the Hallucination Tunic
Confuse an NPC by naming yourself Lance
Beat the "1 Dungeon" challenge
Play a challenge
Get the "Perfect" ending
Save Lance
Save the Elder
Defeat Delvin without killing him
Bring powered-up Henrietta to the fight with Delvin
Defeat the Chairman without killing him
Uncover the whole overworld map
Find a cave within a cave
Defeat a boss without killing it
Get the Binoculars
Get the Error Log
Get the Book of Changes
Cross the world wrap
Get the Patent
Get the Beta Cup
Kill a Whirligig
Do a lightning attack with the Tungsten Sword
Call the developer from in-game
Access a dungeon without defeating the boss in the dungeon before it
Use a potion to skip Lance's death cutscene
Drop a hallucination potion on yourself
Blow up a rock before you obtain the bombs
Play local co-op with a friend
Get the IOU
Double your money in a single trade at the bank
Earn Paige's affections
Unlock Paige as a companion
Drop a beer potion on yourself
Order a pizza
Play Tombs & Tentacles
Do a spin attack with the Damascus Katana
Find a tomb under a gravestone
Get the Police Report
Melt ice before you obtain the lighter
Unlock Shadow Lenna
Empower Henrietta
Kill a boss for the first time
Beat the "3 Hearts" challenge
Beat the "0 Hearts" challenge
Beat the "Arsonist" challenge
Beat the "Bomber" challenge
Beat the "Sniper" challenge
Beat the "Reflex Mode" challenge