what does the ending mean?

[auntiebirdie]

had an absolute blast playing this with my sister, collecting orbs, flying around, turning a forest into golem noodles that filled her with existential dread as they swam below the ocean's surface, 10/10

but after defeating the manticore and watching the ending cutscene then rewatching the opening one, i have a million questions

what?? does it all mean??

is the whole game inside a tear drop of a boy looking at a grave stone? is the grave the same grave the alchemist is grieving at in the beginning? are the boy and the alchemist the same person? or is this a never-ending story scenario where the whole game is just the boy's imagination, where he self-inserted himself into the story?