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