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