This is an idea for a set of major features that would greatly enhance Minecraft.
The features could sell as one more multiple major game extensions on top of the original game. These are major, but they weave together into a general game concept that works as a whole. Plus, it could make a lot of money.
Although these features are not focused around graphical effects, but they would require allowing wider areas of the game to operate simultaneously which would use a lot more computer resources. The hope is that if they are not purchased, the original game would remain mostly intact, and just as usable on low resource computers.
First, Cornerstones Enable Special Buildings
- Relics are added to the original game.
- They can be placed on special stands after they are obtained
- In an extension, players gain the ability to build a "cornerstone creator", which behaves much like an enchanting table.
- Like bookshelves on an enchanting table, this produces stronger cornerstones when surrounded by relic stands with relics.
- Cornerstones can be created.
- Some types of cornerstones require one specific relic.
- Each type of cornerstone pertains to a special building
- Cornerstones are placed at the foundation of these special buildings.
- Cornerstones can only be placed in one x,y,z orientation
- Cornerstones denote how big of an area of blocks constitutes its special building
- Cornerstones denote which player owns that building
- More powerful cornerstones allow greater block areas for a special building
- blocks within that area contribute to attributes of the special building. Thus, a greater area means more effectiveness

Next, Special Buildings Bring New Possibilities

(In Minecraft, these buildings are not all for war strategy, though that is a viable direction this game could take. The game is more about acquiring resources from different biomes and peoples in order to automate and industrialize.)
Now imagine that the internals and effectiveness of these special buildings are up to you to design and advance using what you design.
Custom Algorithms Interface
Some special buildings train settlers or draft animals. Each building can train with only one or two algorithms at a time, and even then separate types of buildings are required for different roles, such as mining, delivering, and soldiering.
Each training building has an interface that facilitates a guided design process to create algorithms for settler trainees to follow. These would introduce kids to graphical, drag n' drop algorithms that they would get to see effect their productivity in the game. There would be incentive to get settlers to do things you used to have to manually do yourself.
These can start out very simple, but get more complex over time. More powerful buildings might be able to train settlers to be more real-time adaptive. Different algorithm construction options would exist for different buildings.
Exciting Design Features
The only new formidable design technique introduced in these extensions is the algorithm interface.
Many special buildings will facilitate the creation of new highly customized devices and vehicles without straying from the classic cube design method of Minecraft. These new player interfaces will vary between each other only slightly, according to what type of device or vehicle the building is for.
Two new methods for designing these types of devices and vehicles via special buildings are called Boxing and Scaling.
Scaling
Scaling means to design something with voxel cubes similar as one would in Creative Mode. However unlike Creative Mode, that design can be manifested in the game, through the pertinent special building, after the player has saved up the necessary resources.
"Scaling" refers to the ability to scale these designs up or down, and adjust the require resources accordingly. Thus platforms and chassis etc. may be designed more finely than one voxel of thickness. Scaling options will be easily transferable such as in 2-to-1, 4-to-1, 8-to-1 and vice versa.
Boxing
Boxing refers to packaging a set of voxels into a "black box" or a function with inputs and outputs.

Inputs and outputs deal with:
- items (anything one can keep in inventory)
- redstone wire connectors
- perhaps more I am not considering
Population Expansion
A big part of these extensions will be about planning and building new towns near settlements, and then upgrading those towns into cities with outlying farms and factories. Towns require walls to be constructed.
Next, it will become important to found towns in different biomes in order to acquire different resources and refine them. You will want to build roads and ships in order to explore and then trade and deliver goods between towns and cities.
All of the expansion will require continued manpower, resources, and infrastructure. Increasing automation through special buildings will make all of these things manageable, but not until after you have wallowed a bit in each area.
Next, it will become important to found towns in different biomes in order to acquire different resources and refine them. You will want to build roads and ships in order to explore and then trade and deliver goods between towns and cities.
All of the expansion will require continued manpower, resources, and infrastructure. Increasing automation through special buildings will make all of these things manageable, but not until after you have wallowed a bit in each area.
War Strategy
Perhaps in the process of expansion, a town or city brakes off on its own. Perhaps there is a multiplayer option. Either way, war strategy can become a thing. In this case, Minecraft needs to be able to facilitate a large-scale zoom-out on the landscape to enable a WarCraft-like experience.
Crashed alien ships contain teleportation devices that must be activated to work. When activated, players can go to an alien world or a mothership - or multiple alien worlds. There players will find new technologies and resources.
Crashed Alien Ships
How could you create large Minecraft expansions without adding a new world to explore?Crashed alien ships contain teleportation devices that must be activated to work. When activated, players can go to an alien world or a mothership - or multiple alien worlds. There players will find new technologies and resources.