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