Here is the full list of all 63 Earth Overclocked achievements.
Take no damage in a run
Take no damage in a run in Earth Unleashed
Finish a run in under 12 in-game minutes
Finish a run in under 10 in-game minutes
Beat the Time Empress
Yep. (only need the Singleplayer ones)
Finish Earth Unleashed in the Birthday Suit
In the Magnet suit, have 15 hearts follow you at once
Finish Earth Unleashed in the Gym Suit
Lose 50 runs
Finish Earth Unleashed in the Magnet Suit
Finish Earth Unleashed in the Ninja Suit
Finish Earth Unleashed in the Scientist Suit
Defeat Elemental Meiun
Defeat a Bombcano
Use the Sheep weapon on an enemy
Finish a run in the Birthday Suit
Score 50,000 with the Birthday Suit
Beat the final boss
Defeat the rare Slendy
Finish a run in the Gym Suit
Defeat Frozen Bones
In the Gym suit, defeat a boss with both weapons at full weight
Finish a run in the Magnet Suit
Finish a run in the Ninja Suit
Finish a run in under 15 in-game minutes
Buy the most expensive weapon from a merchant
Score 200,000 points
Defeat Mystery
Defeat Zombakuto
Defeat the rare Benny
Defeat the Blob Bros.
Defeat Meteor Bob
Defeat Treebot
Finish a run in the Scientist Suit
In the Scientist suit, complete a run without using the revive potion
Defeat Meiun
Defeat a Sandstorm
Collect all of the contents in the Mega Slot Chests
Defeat Skeleking
Defeat the rare Chucab
Score 50,000 with the Gym Suit
Defeat a Tree Monster
Score 50,000 with the Magnet Suit
Defeat the rare Mothguy
Defeat the Night Emperor
Score 50,000 with the Ninja Suit
Defeat the special Gold Blob
Defeat a Crystal Heart
In the Ninja suit, defeat a boss without using either attack button
Delay the Apocalypse by 6 minutes in one run
Delay the Apocalypse by 4 minutes in one run
Defeat the Soul of Raynald
Defeat Zombakuto BW
Defeat one of Meiun's Advocates
Defeat Foreman Jack
Defeat the rare Jef
Delay the Apocalypse by 150 seconds in one run
Defeat a Yeti
Defeat a Wumbo Blob
Score 50,000 with the Scientist Suit
Defeat the Royal Dillos
Run into the instant death spikes