Here is the full list of all 30 101 Ways to Die achievements.
Complete a Basement level
Complete tutorials
Kill your first Splatt
Discover your first WTD
First combo
Claim your first 50 victims
Spill 1000 litres of blood
Flatten 50 Splatts with a Boulder
Claim your first 101 victims
Claim your first 1000 victims
NCompleted Basement Laboratories
Completed Control Room Laboratories
Completed Bio Zone Laboratories
Completed Sector Zero Laboratories
Discover 10 WTDs
Discover 50 WTDs
Discover all 101 WTDs
Achieve a x4 combo
Completed all Graduate and Master objectives in a Laboratory
Achieved a three star rating for all Laboratories in any Sector
Earned three stars in all Laboratories in every Sector
Achieved your first Three Star rating in a lab
Amassed 100 Stars
Kill 50 Splatts with the Cannon
100 Splatts impaled on Spikes
50 Splatts killed in a Lava Pit
Kill a Splatt whilst it's stunned
10 Cakes completely consumed
Completed all Sectors
Kill a Tank, Alpha and a Rapid within one second