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