Here is the full list of all 55 Pixel Heroes: Byte & Magic achievements.
Defeat the inscrutable flying polyp.
Lose 10 times.
Defeat the boss of the Haunted Mansion.
Defeat three enemies with one hit.
Revive 3 fallen heroes during one adventure.
Defeat the boss of the Stormy Peaks.
Reach 500 HP with one hero.
Defeat the boss of Old Volcano.
Use 50 potions during one adventure.
Survive through 3 dungeons in a row.
Defeat the boss of the Goblin Outpost.
Enter a bossfight with two alive heroes and be victorious.
Unlock a treasure chest with no more than 20% chance.
Defeat the boss of the Ancient Temple.
Listen to Layment, the travelling musicians.
Defeat the boss of the Byting Woods.
Defeat the boss of the DevilsReef.
Defeat an enemy only with the fist.
Listen to all stories of the barkeeper.
Drink 100 glasses of beer during one adventure.
Finish your first quest.
Defeat the boss of the Arcane Armory.
Lose all your heroes for the first time.
Defeat your first enemy.
Evade an attack by the use of Concealed.
Defeat the boss of The Boneyard.
Defeat the boss of the Cyclopean Pyramid.
Defeat the boss of the Randoom Meteorite.
Defeat the boss of the Gates of Ashtur.
Help Mustachio on his path to self-fulfillment.
Help Captain Capslock on his path to self-fulfillment.
Help Sapphire on her path to self-fulfillment.
Help Shroom on his path to self-fulfillment.
Help Jindid on his path to self-fulfillment.
Finish a complete adventure without dying once.
Defeat the captor of souls himself.
Defeat the boss of the Sunken Empire.
Lose 50 times.
Lose 100 times.
Finish an adventure with an all-Human party.
Finish an adventure with an all-Dwarf party.
Finish an adventure with an all-Skyborn party.
Finish 6 dungeons during one adventure.
Uncover the dark secret of the casino owner.
Finish an adventure with Herbalist, Priest and Brewmaster.
Finish an adventure with Fighter, Barbarian and Warrioress.
Finish an adventure with Enchantress, Shadowmancer and Skyweaver.
Solve all four riddles of the enigmatic idols.
Finish the final campaign without a hero dying.
Lead all citizens to maximum happiness.
Unlock all hero classes.
Play at least once with each hero class.
Finish an adventure with each hero class.
Escape the red flyswarm 4 times.
Enter a bossfight with a single alive hero and be victorious.