A lot of the illustrations somehow remind me of the "Of mana" series of video games. ^.-
I get what you mean. I only got to play Sword of Mana when I was little, but I've always loved to look at artwork from all the different Mana games. There's a similar softness and tenderness to how Tsukushi draws landscapes and cute things. Plus the sort of wildness of nature, with lots of chaotic, organic shapes. The Mana games and Made in Abyss have that in common with their artwork.
Looking at the Seventh Layer for the first time, I can't seem to decide what it is. Sometimes it looks like a softly detailed grassy field. Sometimes it looks like ocean waves. Sometimes it looks like clouds. And sometimes it looks like innards. I'm scared, but intriguied what colors Tsukushi will choose for it.
And I'm even more scared and even more intrigued what the curse does in the Seventh Layer. Last chapter Srajo said something about how death isn't really the effect, it's a placeholder used to hide it or simply because it's poorly understood. If it's somehow more horrific and esoteric than being transformed into a Narehate, then I have a hard time picturing what it could even be.