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.
Find all blueprints (purchase not necessary).
Beat the game... twice.
Mock the traitor.
Defeat the brothers.
Defeat the son.
Defeat the trademarked chemical.
Defeat the asteroids.
Defeat the last boss.
Defeat the boss in the Land of Darkness.
Defeat the doppleganger.
Play the game for at least 20 hours.
Find all the runes (purchase not necessary).
Defeat the boss in the Maya.
Defeat all the minibosses.
Use the special class at least once.
Read the last journal entry.
Put at least one point in every skill in the manor.
Defeat the boss in the Forest Abkhazia.
Beat one of the clown's games at least once.
Reach level 50 or higher.
Have one rune equipped in every item slot.
Kill a chicken.
Defeat the boss in Castle Hamson.
Earn your very first Enchantress rune.
Open your very first gold chest.
Have one piece of equipment in every item slot.
Die 20 times or more.
Choose a hero with no traits.
WITHOUT using the Architect, complete the game dying 15 times or less