I very much enjoyed the pace of this story. Upon first read, I figured the wormhole had merely transported him far ahead in time (but to the same planet of departure). Then I figured the wormhole may have transported him to an alternate dimension/different version of his planet of departure. I am not certain which best aligns with wormhole theory...

I would assume the latter since there seems to be various instances in the story hinting that the physics of this place is a bit out of whack: the way he kicks the grass and it bounces back into place; the way the spaceship seems to recede unusually quickly into the horizon as he walks.