Here is the full list of all 19 Volatile Triangle achievements.
Die 1 time
Die 100 times
Die 1000 times
Die 10000 times
Chapter 1 Completed
Chapter 2 Completed
Chapter 3 Completed
Chapter 4 Completed
Chapter 5 Completed
Chapter 6 Completed
Complete a level with more then 1 player.
Die 100 times on 1 level.
Beat a level with a better than perfect score.
Use a launch pad.
Use a sticky pad.
Complete level 24-4 without dying and with a perfect score.
Complete all levels.
Complete all levels with a perfect score.
Use a portal.