Here is the full list of all 47 DROD: The Second Sky achievements.
Looking for hard questions
Completed all of Arky's challenge rooms
Complete the quest for the plate
Be mean in HitF
Be kind in HitF
Complete Chapter 8
Complete Chapter 9
Complete Chapter 7
Complete Chapter 6
Complete Chapter 5
Complete Chapter 4
Complete Chapter 3
Complete Chapter 2
Receive an answer from the Truth Vessels
Saw the second sky
Complete Chapter 1
Completed D level
Kill a man-eating dungeon roach
Complete the challenge in TRA
Complete the challenge in MOAR
Completed Bomberman challenge
Completed Roachu Rocket challenge
Complete the final chapter
The end of the journey
Touch the secret checkpoint in FW
Completed R level
Completed FB level
Complete the challenge in S.Ga.
Complete the challenge in WBCEND:1N1E
Complete the challenge in WBCEND:1E
Complete the challenge in EoA:2E
Complete the challenge in EotS
Complete the challenge in EoA:3S
Complete the challenge in SM:4E
Complete the challenge in SM:1E
Clear the secret area in SutO
Complete the challenge in HitF
Complete the challenge in IU:1N
Complete the challenge in SWaRBS
Complete the challenge in GG
Complete the challenge in TH:1N5W
Complete the challenge in TH:2S1W
Complete the challenge in TO
Complete the challenge in CW
Step kindly all the way through TLW
Completed BM level
Completed The Second Sky and cleared all secret rooms