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