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