Here is the full list of all 21 Lair of the Clockwork God achievements.
Comment on four invisible walls
Suffer through a wild goose chase
Get Everyone Killed
Make it through the final escape without dying
Read all the Luxomails
Input the colours code before you know it
The Army Of Daftness
Discover Balloon-Head's origin story
Just barely get a grip.
Kill 30 pinions
Get a different kind of angry
Give Ben both barrels
Get Hairy Palms
Teleport a very small distance
Taste all the flavours of lollipop
Beat the Choo-Choo Train
Look at you, so so clever breaking the rules.
Watch 100 splash logos
Turn Vi four colours
Find the worst joke in the game
Make it through London without dying