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
Find all blueprints (purchase not necessary).
Beat the game... twice.
Play the game for at least 20 hours.
Find all the runes (purchase not necessary).
Defeat the last boss.
Mock the traitor.
Defeat the brothers.
Defeat the asteroids.
Defeat the trademarked chemical.
Defeat the boss in the Land of Darkness.
Defeat the son.
Beat one of the clown's games at least once.
Defeat the boss in the Maya.
Defeat all the minibosses.
Defeat the boss in the Forest Abkhazia.
Put at least one point in every skill in the manor.
Read the last journal entry.
Kill a chicken.
Use the special class at least once.
Reach level 50 or higher.
Open your very first gold chest.
Have one rune equipped in every item slot.
Defeat the doppleganger.
Defeat the boss in Castle Hamson.
Have one piece of equipment in every item slot.
Die 20 times or more.
Choose a hero with no traits.
Earn your very first Enchantress rune.