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