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