Here is the full list of all 54 Spiral Knights achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Hit an opponent with a snowball in Lockdown.
Obtain a Firecracker bomb.
Amass 10 guns in your Arsenal.
Amass 10 swords in your Arsenal.
Amass 5 swords in your Arsenal.
Amass 5 guns in your Arsenal.
Amass 5 helmets in your Arsenal.
Amass 5 shields in your Arsenal.
Alchemize a 1 star item.
Build an item to heat level 10.
Use 10 Health Capsules.
Alchemize a 2 star item.
Amass 5 armors in your Arsenal.
Amass 3 bombs in your Arsenal.
Amass 3 guns in your Arsenal.
Amass 3 swords in your Arsenal.
Amass 3 shields in your Arsenal.
Amass 3 helmets in your Arsenal.
Amass 3 armors in your Arsenal.
Revive a downed party member.
Pay a visit to Moorcraft Manor.
Revive yourself.
Power up a derelict Mecha Knight.
Reach the first Clockworks Terminal.
Cross the chasm into Haven.
Successfully reach the Rescue Camp.
Earn clearance to explore Tier 2 of the Clockworks.
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.
Defeat the fabled Snarbolax that lives deep within the Gloaming Wildwoods.
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 5 bombs in your Arsenal.
Amass 10 bombs in your Arsenal.
Amass 10 helmets in your Arsenal.
Amass 10 armors in your Arsenal.
Amass 10 shields in your Arsenal.
Amass an Arsenal that includes a 5 star helmet, armor, shield, gun and bomb.
Unlock and fill every equipment slot.
Use 10 Remedy Capsules.
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.