my idea is that you start a world with the option of "The Beginning".

this would be where you just float around in a space of eternal black but with light.
over time you will find a new element every now and then which you can then turn into a substance by adding it with other elements by putting it in your inventory and take out the product via another slot.
the product of this would be a block of that substance that you can then place beneath yourself via pressing "V".

After this that block will attract other elements of the table in witch you cane place on the "Origin Block".
this is ever increasing the pull of blocks.
after you have acquired certain elements you will start to be able to form other types of blocks that naturally occur in the mine craft world.
from this you will pretty much be on a skyblock type of world and from this you would be able to set your own objectives and of course to complete the entire periodic table.