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