Here is the full list of all 58 Horace achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Find all the alternate title screen skins.
Push all the rubber ducks into the water in the Laundry Room.
Read 15 teletext pages.
Score 100 baskets in total.
Reach the end of the game having cleaned one million things.
Complete the auto map by visiting every room in the mansion.
Clean 1000000 things.
Find all the secret rooms in the mansion.
Clean 100000 things.
Save the Man in Black.
Don't save the Man in Black.
Watch a train arrive and leave at any station.
Win The One Tournament.
Defeat the helicopter boss.
Travel to the secret moon base.
Defeat the Ether boss.
Buy all possible shop items..
Catch 200 objects.
Defeat the Water boss.
Die 1000 times.
Defeat the Fire boss.
Defeat the Earth boss.
Find a secret room in the mansion.
Defeat the Air boss.
Find an alternate title screen skin.
Reunite with Heather and the Old Lady.
Go on a most excellent adventure with the Professor.
Earn £10000 from jobs, junk yards and other winnings.
Meet up with Alice and Sim.
Kidnap Mr Deck from the TV Studio.
Clean 10000 things.
Take your first train ride.
Help to sort the post.
Buy an item from a shop.
Play an arcade game.
Help to make bricks.
Earn £1000 from jobs, junk yards and other winnings.
Earn £100 from jobs, junk yards and other winnings.
Help to wash dishes.
Complete all other achievements.
Spring Logan from prison.
Learn to play the drums.
Empty 10 bins.
Defeat the Nanobot Boss.
Defeat the K-Bot 100 Boss.
Use the Atlas Gloves to tidy up the village hall.
Of dead Old Men?
Rescue the family from the burning house.
Return the blind man's cat.
Venture out of the mansion.
Clean 1000 things.
Clean up your first thing.
Completed basic robot training.
Climb walls with the Shoees for the first time.
Complete the game.
Get the high score on all the arcade games.
Get the kids blamed for shop lifting.
Run the BASIC program everybody knows and loves...