Here is the full list of all 54 Spiral Knights achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Use 10 Health Capsules.
Amass 5 guns in your Arsenal.
Alchemize a 1 star item.
Amass 3 helmets in your Arsenal.
Amass 5 swords in your Arsenal.
Amass 3 guns in your Arsenal.
Cross the chasm into Haven.
Amass 3 armors in your Arsenal.
Amass 3 swords in your Arsenal.
Successfully reach the Rescue Camp.
Reach the first Clockworks Terminal.
Pay a visit to Moorcraft Manor.
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 2 star item.
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 3 bombs 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 3 shields 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 yourself.
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.
Obtain a Firecracker bomb.
Hit an opponent with a snowball in Lockdown.