Here is the full list of all 27 Super Pig X achievements.
Killed 10 pigs
Killed 1 pig
Killed 100 pigs
Killed 1000 pigs
Ate 1 bacon
Ate 10 bacons
Ate 100 Bacon
Found Dark Bacon
Found 10 Dark Bacon
Found 50 Dark Bacon
Perfected a level
Perfected 10 levels
Beaten Level 1-X
Beaten Level 2-X
Beaten Level 3-X
Beaten Level 4-X
Beaten Level X-X
Beaten Level Z-X
Beaten Level 0-X
Beaten The Game
Beaten All Levels
Enable Vegan Mode
Cheated
Enabled XP mode
Loaded Custom Level
Found Secret Exit
Perfected all levels