Here is the full list of all 221 Army of Ruin achievements.
Upgrade Pirate Cutlass to Level 5
Glacier III - Complete the Stage with no Capacity Upgrades
Graveyard III - Complete the Stage spending 20,000 or less in Upgrades
Forge I - Complete the Stage without purchasing any Upgrade
Forest II - Complete the Stage spending 5,000 or less in Upgrades
Glacier Stage ∞ - Reach Minute 30
Forest III - Complete the Stage without taking any damage
Glacier II - Complete the Stage without moving
Forge III - Complete the Stage without opening any chest
Forge II - Complete the Stage with 22:00 minutes or more on the clock
Forest I - Complete the Stage with 16:00 minutes or more on the clock
Upgrade Anvil of Heaven to Level 5
Graveyard II - Complete the Stage without taking any damage
Glacier I - Complete the Stage without taking any damage
Shrine ∞ - Reach Minute 30
Upgrade Hitman Goggles to Level 5
Upgrade Brittle Stone to Level 5
Shrine I - Complete the Stage without moving
Reach Experience Level 30 with Diana
Upgrade Bronze Starfish to Level 5
Shrine II - Complete the Stage without opening any chest
Reach Experience Level 30 with Michi
Upgrade Throwing Bombs to Level 5
Upgrade Command Baton to Level 5
Reach Experience Level 40 with Midas
Upgrade Living Paintbrush to Level 5
Shrine III - Complete the Stage with 28:00 minutes or more on the clock
Forge Stage ∞ - Reach Minute 30
Reach Experience Level 40 with Neptune
Upgrade Caltrops to Level 5
Reach Experience Level 40 with Azazel
Upgrade Chain Lightning to Level 5
Shrine III - Ruin 3 - Evolve 3 weapons with Abaddon
Graveyard I - Complete the Stage without moving
Reach Experience Level 30 with Traxx
Upgrade Chain Shot to Level 5
Upgrade Dark Staff to Level 5
Upgrade Jade Wand to Level 5
Unlock 200 items (Characters, Equipment and Features)
Reach Experience Level 30 with Nekros
Upgrade Marksman's Crossbow to Level 5
Upgrade Unfulfilled Promises to Level 5
Reach Experience Level 25 with Tabia
Forest Stage ∞ - Reach Minute 30
Shrine II - Complete the Stage with Rotting Coil,Poison Root,Elven Bow
Upgrade Divine Top to Level 5
Shrine III - Ruin 1 - Complete the Stage with Magic Needle
Shrine III - Complete the Stage infusing Wind Wind Wind
Upgrade Lapis Sword to Level 5
Shrine III - Complete the Stage without infusing any Earth
Upgrade Fiendish Tear to Level 5
Shrine III - Complete the Stage
Graveyard Stage ∞ - Reach Minute 30
Shrine I - Ruin 1 - Complete the Stage with Devilish Eye
Pick 3 Charms
Glacier Stage III - Ruin 3 - Pick 3 Charms with Kroat
Glacier Stage III - Ruin 2 - Reach Experience Level 35 with Bhask
Glacier Stage III - Ruin 1 - Complete the Stage with Frozen Shard
Glacier Stage III - Earn 4,000 Coins with Homemade Explosives
Upgrade Swift Tornado to Level 5
Glacier Stage II - Ruin 1 - Complete the Stage with Supply Crate
Upgrade Wanderer's Lantern to Level 5
Glacier Stage I - Ruin 1 - Complete the Stage with Obsidian Crown
Forge Stage III - Ruin 3 - Complete the Stage with Toxic Stench
Forge Stage III - Ruin 1 - Complete the Stage with Ancestral Razor
Forge Stage II - Ruin 3 - Upgrade Panacea to Level 5
Forge Stage II - Ruin 2 - Complete the Stage with Jellyfish Ashes
Forge Stage I - Ruin 3 - Complete the Stage with Pirate Anchor
Forest Stage II - Ruin 3 - Earn 4,000 Coins with Saul
Forest Stage II - Ruin 2 - Complete the Stage with Buckler
Upgrade Battle Cog to Level 5
Forest Stage II - Ruin 1 - Complete the Stage with Bhask
Graveyard Stage III - Ruin 3 - Defeat all special bosses with Obsidian Crown
Upgrade Ominous Gale to Level 5
Reach Experience Level 25 with Kroat
Forge Stage III - Ruin 2 - Complete the Stage with Mork, and infuse Fire Fire Fire
Reach Experience Level 25 with Mork
Upgrade Mighty Punch to Level 5
Glacier Stage II - Ruin 2 - Complete the Stage with Tisha and Explosive Flask,Seal of Purity
Upgrade Magatama to Level 5
Forest Stage III - Ruin 1 - Defeat all special bosses with Lanyz
Glacier Stage II - Ruin 3 - Earn 5,000 Coins with Neptune
Upgrade Ink Geyser to Level 5
Graveyard Stage III - Ruin 2 - Defeat all special bosses with Experiment XIX
Reach Experience Level 40 with Experiment XIX
Forest Stage III - Ruin 2 - Defeat all special bosses with Bhask
Upgrade Jellyfish Ashes to Level 5
Unlock 150 items (Characters, Equipment and Features)
Forest Stage III - Ruin 3 - Reach Experience Level 40 with Tisha
Shrine II - Complete the Stage infusing Ice Ice Ice
Upgrade Sparksword to Level 5
Upgrade Landslide to Level 5
Glacier Stage III - Complete the Stage without infusing any Earth
Glacier Stage III - Complete the Stage
Upgrade Ancestral Razor to Level 5
Forge Stage III - Upgrade Leather Bracer to Level 5
Forge Stage III - Upgrade Golden Trident to Level 5
Forge Stage III - Complete the Stage
Forest Stage III - Upgrade Ranger Bow to Level 5
Upgrade Magical Slingshot to Level 5
Forest Stage III - Complete the Stage with Meteorite Blast
Reach Experience Level 40 with Samael
Forest Stage III - Complete the Stage
Reach Experience Level 40 with Abaddon
Upgrade Sphere of Destruction to Level 5
Shrine II - Ruin 2 - Defeat all special bosses with Samael
Shrine II - Complete the Stage
Shrine II - Ruin 1 - Complete the Stage with Onyx Coin
Upgrade Fire Wings to Level 5
Upgrade Pirate Anchor to Level 5
Glacier Stage I - Ruin 3 - Evolve 3 weapons with Kyros
Forge Stage II - Ruin 1 - Defeat all special bosses with Ogol
Glacier Stage I - Ruin 2 - Complete the Stage with Selina, without infusing any Darkness
Glacier Stage II - Complete the Stage with War Drums
Earn 30 Stars
Glacier Stage II - Evolve Necromancer Gauntlets
Glacier Stage II - Complete the Stage
Shrine I - Upgrade Wolf's Fang to Level 5
Upgrade Mystical Firecrackers to Level 5
Upgrade Promethean Flames to Level 5
Shrine I - Upgrade Ice Tear to Level 5
Upgrade Ghostly Trail to Level 5
Shrine I - Complete the Stage
Graveyard Stage II - Ruin 3 - Kill 7500 enemies
Forest Stage I - Ruin 3 - Complete the Stage with Voodoo Doll
Upgrade Frozen Shard to Level 5
Graveyard Stage III - Ruin 1 - Complete the Stage with Ker
Graveyard Stage III - Reach Experience Level 30 with Ker
Graveyard Stage I - Ruin 3 - Reach Experience Level 30 with Lanyz
Reach Experience Level 25 with Kyros
Upgrade Fire Staff to Level 5
Reach Experience Level 25 with Tisha
Upgrade Cupid's Arrow to Level 5
Upgrade Ranger Bow to Level 5
Graveyard Stage II - Ruin 2 - Defeat all special bosses with Ker
Reach Experience Level 15 with Ker
Graveyard Stage III - Complete the Stage
Evolve 4 weapons
Graveyard Stage III - Complete the Stage with Storm Javelin
Unlock 100 items (Characters, Equipment and Features)
Upgrade Silvan Shell to Level 5
Forge Stage I - Ruin 2 - Complete the Stage with Ice Mirror
Forge Stage I - Ruin 1 - Complete the Stage with Lanyz
Pick 1 Charms
Earn 21 Stars
Glacier Stage I - Upgrade Toxic Stench to Level 5
Earn 20 Stars
Glacier Stage I - Reach Experience Level 25 with Ogol
Glacier Stage I - Complete the Stage
Earn 18 Stars
Forge Stage I - Upgrade Magnifier to Level 5
Graveyard Stage II - Ruin 1 - Defeat all special bosses with Ariana
Forest Stage I - Ruin 1 - Defeat all special bosses with Saul
Upgrade Homemade Explosives to Level 5
Use the Bomb Power 10 times through all stages
Graveyard Stage I - Ruin 2 - Complete the Stage with Whirlwind Pickaxe
Unlock 60 pieces of equipment (Weapons and Trinkets)
Forge Stage II - Reach Experience Level 30 with Ogol
Use your skill 200 times through all stages
Earn 17 Stars
Use the Haste Power 10 times through all stages
Reach Experience Level 15 with Bhask
Upgrade Blaze to Level 5
Forest Stage II - Upgrade Armor of Thorns to Level 5
Earn 16 Stars
Earn 15 Stars
Forest Stage II - Complete the Stage with Energy Bolt
Defeat 100 bosses through all stages
Forge Stage II - Reach Experience Level 30 with Saul
Upgrade Spectral Dagger to Level 5
Upgrade Toxic Stench to Level 5
Upgrade Storm Javelin to Level 5
Forge Stage II - Complete the Stage
Earn 12 Stars
Use your skill 15 times
Forge Stage I - Complete the Stage
Use the Freeze Power 10 times through all stages
Reach Experience Level 15 with Lanyz
Upgrade Meteorite Blast to Level 5
Earn 10 Stars
Earn 30,000 Coins through all stages
Upgrade Wolf's Fang to Level 5
Upgrade Flintlock Pistols to Level 5
Upgrade Quicksilver Spears to Level 5
Unlock 50 items (Characters, Equipment and Features)
Win a total of 6 stages
Forest Stage II - Complete the Stage
Graveyard Stage I - Ruin 1 - Complete the Stage with Viking Helm
Upgrade Whirlwind Pickaxe to Level 5
Die a total of 10 times
Forge Stage I - Earn 750 Coins
Earn 20,000 Coins through all stages
Graveyard Stage II - Upgrade Travel Boots to Level 5
Upgrade Golden Trident to Level 5
Die a total of 5 times
Earn 8 Stars
Graveyard Stage II - Complete the Stage with Magic Staff
Upgrade Crawling Root to Level 5
Upgrade Energy Bolt to Level 5
Graveyard Stage II - Complete the Stage
Earn 5 Stars
Kill 3000 enemies
Forest Stage I - Upgrade Volcanic Orbs to Level 5
Upgrade Throwing Axe to Level 5
Reach Experience Level 15 with Saul
Upgrade Magic Staff to Level 5
Upgrade Volcanic Orbs to Level 5
Forest Stage I - Complete the Stage with Throwing Axe
Upgrade Necromancer Gauntlets to Level 5
Forest Stage I - Complete the Stage
Reach Experience Level 15 with Ogol
Graveyard Stage I - Upgrade Crawling Root to Level 4
Earn 500 Coins
Reach Experience Level 25
Open 5 Chests
Earn 5,000 Coins through all stages
Earn 2 Stars
Graveyard Stage I - Reach Experience Level 20 with Ariana
Upgrade Dragon Heart to Level 5
Graveyard Stage I - Complete the Stage
Reach Experience Level 15 with Ariana