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