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