Missable Achievements (16):
Everything Must Go + Spill the Beans - the Nick's Bricks saga
A Lovely Pair - mow the lawn
Mole Supper - get disinvited by the mole
Sick as a Fig - put the locksmith in recovery position
A Fine Mess - mess up Shaggers shelves
Done Up Like a Kipper - give the fishmonger a hand(y)
Cheek to Cheek - butt smacking
Lights Out - bully Charlie
Final Form - get all ham bits
Menage a trois - you know what this means
Green Fingers - kill the mother flower
The Ol' One Two - get the cop to throw eggs
Think F.A.S.T. - learn about alcoholism
Tough Tatties - hear the potatoes' story
Shell Shocked - kill all 7 snails

Collectibles Achievements (4):
No Post on Thuesdays - 6 postboxes
Bobby Knocker - knock on doors (8? required)
The Rat Pack - 3 singing mice packs
Friend of the Forest - find all the animals (mole, stoat, owl, mice, ducks)

Unmissable Story Achievements (11)
7 title card achievements
Credits
Visit Barnsworth
The Beans are on the Windowsill
The People's Princess - break Lady Di