Playing Act IV again

[Opalescence]

Is there specific significance to playing Act IV again for the developers to make an achievement out of it? I played it again just to see whether there was a difference in Conway's arc and haven't come across any.

[eli]

You can either stay on the boat or go onto shore in a variety of locations. You can't see everything in the act if you only play it once, so it's encouraging you to do it twice and make the opposite choices so you can see everything.