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