Here is the full list of all 54 Spiral Knights achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Alchemize a 2 star item.
Amass 3 shields in your Arsenal.
Earn clearance to explore Tier 2 of the Clockworks.
Amass 3 bombs in your Arsenal.
Use 10 Health Capsules.
Obtain a Firecracker bomb.
Alchemize a 1 star item.
Pay a visit to Moorcraft Manor.
Defeat the fabled Snarbolax that lives deep within the Gloaming Wildwoods.
Reach the first Clockworks Terminal.
Revive yourself.
Amass 5 guns in your Arsenal.
Amass 3 helmets in your Arsenal.
Cross the chasm into Haven.
Amass 5 swords in your Arsenal.
Amass 3 armors in your Arsenal.
Amass 3 guns in your Arsenal.
Amass 3 swords in your Arsenal.
Successfully reach the Rescue Camp.
Pay a visit to Emberlight, the town of gremlin outcasts.
Earn clearance to explore Tier 3 of the Clockworks.
Descend to the Core Terminal.
Defeat the Royal Jelly squatting in the Royal Jelly Palace.
Defeat Lord Vanaduke in the heart of the Firestorm Citadel.
Alchemize a 3 star item.
Alchemize a 4 star item.
Alchemize a 5 star item.
Alchemize 5 items.
Alchemize 10 items.
Alchemize 25 items.
Alchemize 50 items.
Amass 10 swords in your Arsenal.
Amass 10 guns in your Arsenal.
Amass 5 bombs in your Arsenal.
Amass 10 bombs in your Arsenal.
Amass 5 helmets in your Arsenal.
Amass 10 helmets in your Arsenal.
Amass 5 armors in your Arsenal.
Amass 10 armors in your Arsenal.
Amass 5 shields in your Arsenal.
Amass 10 shields in your Arsenal.
Amass an Arsenal that includes a 5 star helmet, armor, shield, gun and bomb.
Build an item to heat level 10.
Unlock and fill every equipment slot.
Revive a downed party member.
Use 10 Remedy Capsules.
Power up a derelict Mecha Knight.
Complete a Tier 1 expedition without having to revive.
Complete a Tier 2 expedition without having to revive.
Complete a Tier 3 expedition without having to revive.
Travel the entire Clockworks from depth 0 to depth 29 in a single expedition.
Travel the entire Clockworks from depth 0 to depth 29 in a single expedition without having to revive.
Defeat the Roarmulus Twins.
Hit an opponent with a snowball in Lockdown.