I wonder if grandpa is really dead. The beginning video implies he died, but we don't see his body or actual death. There's also no other ghosts than grandpa's "ghost".
Hate to burst your bubble but there are ghost enemies in the mines. Also ghost fish.
OK, my conspiracy theory for SDV.
YOU NEVER STOPPED WORKING FOR JOJA CORP.
The owner, (Mr. Qi), earmarked you for his pet project. You got brainwashed into thinking you inherited a farm from a grandfather, and that you are fighting the Evil Corp. while you are actually perpetuating its interests and infiltrating the resistant rustic community of Pelican Town.
You are the sleeper agent for Joja.
This is most likely the true story of Stardew. Grandpa was never really your grandpa, but rather part of your adoptive family, all of whom work for Joja. That's why your parents don't visit you. They are under orders to leave you be. But rather than it being an "infiltration", instead they have set you loose upon the unsuspecting town, seeing in which way you see fit for the town to develop. Which direction it should take and why. Morris, meanwhile, is oblivious to all of this, as a low-ranking Joja underling. Instead, only certain parts of the Corp are aware of this, and represent a separate section/cell/faction of Joja not known about by the majority of it's employees.
Also Sandy is secretly best girl but under orders from Qi to not visit the valley. If Qi is the true antagonist/prime mover of events in the valley, or if he's simply working for someone else, well that remains to be seen.
However, I do wish they'd stop importing their robotic parrots into the valley/ginger island. *cue the 'all birds have been replaced by drones' conspiracy*
