You should read the article, he wanted to give terraria and starbound more of a point.
"It Lurks Below combines Diablo-style dungeon-plumbing mechanics with sandbox-style worlds that let players dig and construct, à la Terraria and Minecraft. In an interview with Polygon, Brevik said he’s a big fan of those games (and Starbound), but wanted to add something of his own to the genre.
“I wanted more of a point to a lot of those games,” Brevik said. “I wanted to make an RPG, with classes and leveling up, random items, where you get more and more powerful as you go down into the core of the world and fight baddies.”"
"It Lurks Below combines Diablo-style dungeon-plumbing mechanics with sandbox-style worlds that let players dig and construct, à la Terraria and Minecraft. In an interview with Polygon, Brevik said he’s a big fan of those games (and Starbound), but wanted to add something of his own to the genre.
“I wanted more of a point to a lot of those games,” Brevik said. “I wanted to make an RPG, with classes and leveling up, random items, where you get more and more powerful as you go down into the core of the world and fight baddies.”"