Lotus is based on the (currently) private source for Revenge of the Starmen and will also be borrowing a number of improvements from Once An Hour (e.g., a config file).
The main addition to Lotus is a type of "home base" or town. The player begins her quest at the doorstep of a small trading post built on top of a labyrinthine maze full of traps, treasures, and monsters. By delving into the dungeon, the player can return to the surface and improve the lonely trading post into a full town.
Note that Lotus isn't trying to be Stardew Valley or Animal Crossing. The systems for interacting with the town are going to be fairly abstract. The player won't be chopping down logs and gathering stone to slowly build up a mountain home. Instead, she'll directly add new buildings to the town with gold and interact with those buildings with a small handful of other materials.
Slice and dice
Lotus is not using the combo "step" system introduced in Grid and being refined for Revenge of the Starmen. Instead, it's using a more traditional system with damage ranges and hit chances - for both the player and enemies.
One of the buildings the player will be able to acquire is the Forge. The functionality of the Forge is inspired by Dark Souls and a handful of other JRPGs. The player can bring certain types of minerals to the Forge to improve the raw quality of her weapons & armor. She can also apply and improve elemental effects on that same equipment.
Lotus will feature 3 classic attributes: Agility, Dexterity, and Strength. Agility improves the player's chance to dodge. Dexterity improves her chance to land blows and Strength improves her ability to hit hard. Pretty standard stuff, right? Not quite.
Direct chance modification is left to the player's equipment. Attributes will scale up (and down!) as a percentage. For example, the player might have an AGI of 50%. In that case, there would be a 50% chance for the player's chance to dodge to be rerolled if it would have otherwise failed.
Attributes can be exercised by engaging in combat. An attribute can be exercised once per dungeon floor. When the player descends deeper into the dungeon with an exercised attribute, that attribute will be automatically improved and will no longer be exercised.
Back on the surface, the player can have a Training Ground built. By trading valuable minerals away, the player can have a specific attribute "super-exercised". An attribute exercised in this way will improve even faster than normal, if only for a short while.
Praise the Sun
The last of the three purchasable buildings is the Temple. Here the player can commune with the various deities of the world and improve her magical prowess. This is the least complete element of the design "triangle" for Lotus so far. I'll make another post later in the week going into more depth on the Temple.