The following comes from a Nintendo Dream interview with Producer Hitoshi Yamagami, Director Kenta Nakanishi, Director Toshiyuki Kusakihara and Producer Masahiro Higuchi...
On things abandoned for Awakening/Fates, but could implement into Echoes
Yamagami: Basically, if you repeatedly make games for the same hardware, methodologies and technology progress and you are able to do things that you weren’t able to before. So, things we had to abandon for Awakening were able to make it into Fates. So, as technology advanced during Fates‘ development, there were things we wanted to implement but couldn’t fit by the time we got near the last stages of making the game. As such, it came down to “There’s still something we want to make.”
Kusakihara: Things like dungeons. You could walk around “My Castle” in Fates in full 3D, for instance, but it was very rough and difficult to implement at the time. Things like that eventually led to being able to walk around the dungeons in this game.
Nakanishi: The truth is all the fields were made to be walked around in. When you enter a battle, the camera simply zooms in on where the character is.
Kusakihara: Other than that, we were able to make character proportions look slightly more natural this time around, thanks to the Motion Design crew. With the experience and “know-how” gained from Awakening and Fates, we attempted to make [the people] in both this game and the next one on Switch closer to realistic proportions and movements.
On why Alm is left-handed
Kusakihara: There are various reasons. One reason is that there were little variations in poses characters could have. That’s when we got a proposal from the motion team that we can make plenty of new poses and patterns if the character was simply left handed. Another reason was to make Alm better resemble a hero with the strength to overcome any enemy. Alexander the Great was said to be left handed, so we wanted an image along those lines.
Nakanishi: Alm being left-handed also helped give better contrast to Celica’s brand, so it worked out nicely.
On the main theme
Composing the main theme
Q: So Janis Crunch sings the ending theme?
Nakanishi: The truth is, I only learned about this song when it was prepared to be inserted into the game (laughs). But when I heard it, it was a really nice piece. It was put it in because the staff heard me thinking “It’d be nice if we had another ballad like Fates did.”
Q: A part of it is also used for the title screen. Tell us what the main theme behind “Heritors of Arcadia” is.
Kusakihara: Mila’s death and rebirth. It is the theme of Echoes as a whole, the Age of Gods is coming to an end by man’s own hand, and they shall be the ones to inherit the world from the gods. The lyrics express that kind of sentiment.
Higuchi: It is meant to feel like Mila singing to the humans who shall inherit Valentia from her with references to stars like orbs across the sky.
This is a small snippet of the full interview, which has all sorts of interesting info. Check it out here (thanks Lightchao42!)