(11/32)
To unlock these ones, just play the game:

1. Visit Barnsworth
   
2. In for a Penny
   
3. Enough for Everyone
   
4. The Beans are on the Windowsill!
   
5. Cream of the Crop
   
6. Open for Business
   
7. The People's Princess
   
8. Milk Shy No More
   
9. Still At Large
   
10. Breakfast in Bed
    
11. Thank Goodness it's Over!

(21/32)
I've organized them in the order, so that you can keep in mind which things you have to do early in your play-through.


Lovely Pair
Make sure to jump over the fence near the guy with green overalls the first time you visit the Town Square and interact with the red lawnmower.

Sick as a Fig
Right after the locksmith helps you open Mother Megg's store, slap him until you get the achievement

Mole Supper
Jump the fence on the other side of the park and hit the dirt mounds until the mole invites you to dinner. He will appear again later when you go down the well (a third time) and you'll get the achievement.

Everything Must Go
There is a guy trying to open a store to the bottom left of the town square, hit the shutters he is trying to open. The second time you visit the Town Square hit the wall This is important because it unblocks other achievement down the line.

Bobby Knocker
Hit EVERY door, start early because some doors get opened later in the game so if you don't hit them early you might miss the achievement.

Think F.A.S.T
Visit the pub every time you pass through the town square, at one point the bartender will start to speak about his favorite drinks, listen and you'll get the achievement.

The Ol'One Two
Hit the police cabin the town square every time you pass through the Town Square. Near the end, you'll get the achievement

A Fine Mess
The first time you visit the Price Shaggers store help to "tidy" up the shelves.

Done Up Like a Kipper
Help the fishmonger organize his fish every time you pass through there, be sure to hit EVERY fish the amount of times it takes.

Cheek to Cheek
Hit the butt of the guy working the hamburger stand, it is located to the bottom left of the market. You must do this every time you pass through the area.

Lights Out
When you come back to the garden a second time, there are some boys bullying Charlie...join in.

Final Form
When you enter the meat dimension, slap ALL the meat you find.

Tough Tatties
When chopping the tatters in the fish and chip store, wait until the potatoes are done talking.

Menage a Trois
When helping the gardener open the fertilizer bag, fall to the left of the bag and then keep moving left until you are in the house.

Shell Shocked
Slap ALL the snails when they appear

Spill The Beans
If you completed the Everything Must Go achievement, near the end of the game hit the bean can in the "store".

Green Fingers
Hit ALL the flowers with a face in the area after you receive the advice not to do that.

No Post on Tuesdays
Hit EVERY postbox

The Rat Pack
Find the trio of singing rats three times, they are located in:

• The town square
  
• The Market
  
• Beside the Fish and Chips shop

Friend of the Forest
Talk to ALL the animals:

• Find a Mink in the boxes and the back of Mother Megg's storage room
  
• Find the trio of singing rats at least one time
  
• Find the mole in the town square when you arrive
  
• Find the owl in the tree near the farm
  
• Find the ducks in the creek, hit the toaster to give them bread (I'm not sure if this helps but better safe than sorry)

Patience is a Virtue
Start a new game and wait in the receptionist's office, don't leave the chair. Around 15 minutes later you will complete the game and receive the achievement.