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