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