Here is the full list of all 14 Luciform achievements.
Finish the tutorial
Complete 10 levels in the campaign
Complete 20 levels in the campaign
Complete 30 levels in the campaign
Complete 40 levels in the campaign
Complete 50 levels in the campaign
Defeat The Gorilla
Survive 5 Rounds of the endless & randomly generated level without dying
Survive 10 Rounds of the endless & randomly generated level without dying
Survive 20 Rounds of the endless & randomly generated level without dying
Survive 30 Rounds of the endless & randomly generated level without dying
Survive 40 Rounds of the endless & randomly generated level without dying
Survive 50 Rounds of the endless & randomly generated level without dying
Open every cage on the gorilla's tree