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