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