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