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