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