Here is the full list of all 29 Rogue Legacy achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Mock the traitor.
Defeat the brothers.
Defeat the trademarked chemical.
Defeat the son.
WITHOUT using the Architect, complete the game dying 15 times or less
Find all blueprints (purchase not necessary).
Beat the game... twice.
Defeat the asteroids.
Defeat the doppleganger.
Defeat the last boss.
Read the last journal entry.
Defeat the boss in the Land of Darkness.
Defeat the boss in the Maya.
Play the game for at least 20 hours.
Find all the runes (purchase not necessary).
Put at least one point in every skill in the manor.
Use the special class at least once.
Defeat all the minibosses.
Beat one of the clown's games at least once.
Defeat the boss in the Forest Abkhazia.
Have one piece of equipment in every item slot.
Have one rune equipped in every item slot.
Kill a chicken.
Reach level 50 or higher.
Defeat the boss in Castle Hamson.
Open your very first gold chest.
Die 20 times or more.
Choose a hero with no traits.
Earn your very first Enchantress rune.