Here is the full list of all 35 Critadel achievements.
Enter the Sanctuary for the first time
Beat a boss on the 2nd floor for the first time
Beat a boss on the 4th floor for the first time
Beat a boss on the 6th floor for the first time
Beat a boss on the 8th floor for the first time
Beat a boss on the 10th floor for the first time
Beat Godfather for the first time
Unlock all weapons
Reach Master 1 rank as Nox
Reach Master 1 rank as Alice
Reach Master 1 rank as Anushu
Reach Master 1 rank as all 3 characters
Achieve Rifle type synergy level 6
Achieve Pistol type synergy level 7
Achieve Charge type synergy level 6
Achieve Shotgun type synergy level 6
Achieve Laser type synergy level 3
Achieve Melee type synergy level 3
Achieve Normal type synergy level 7
Achieve Energy type synergy level 7
Achieve Explosive type synergy Level 6
Achieve Freeze type synergy level 6
Achieve Burn type synergy level 6
Achieve Nature Synergy level 6
Achieve Holy synergy level 3
Achieve Void synergy level 3
Obtain Legendary Gun
Obtain Incisor
Obtain Golden Froggy
Obtain all companions
Obtain all foods
Unlock all artifacts
Unlock all attachments
Clear the Boss Rush mode
Clear Level 18 in Hard mode