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