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