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