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