Mana was sort of a different beast and I played it before I even knew about the Atelier series. They are more more story and exploration focused then Mana. I have played both Arland and Dusk. Dusk was a easier overall but did have a bit more of a focused on combat then other Atelier games and a bit of a sad atmosphere. Arland much more light hearted but difficult in ways I found fun the alchemy system is a bit more simple. Hope this helps you know what you want to play first. I liked them both and hope you do too.