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