A brief flexing of my Google Fu revealed my problem. Any world that is switched from survival to creative mode is locked out of achievements, even after switching back to survival. I had made the switch to creative at one point so I could use the flying ability, handy when building a house in the air.
But I wanted those achievements. They would be reflected on my Xbox profile and help my score there (I certainly haven't been spending any time on my Xbox to do that). Also, spawning was rather messed up, as no hostile mobs would spawn on the island my house floated over.
So a new world was in order. I spawned next to an ocean with a cave system nearby. A river splits the land creating a massive peninsula across the way. And not too far was a beautiful forest filled with mighty Spruce trees. My path was clear, it was time to build a tree house!
I ended up with a three story contemporary structure with a penthouse bedroom. The second floor is my storage and smelting area, and the first floor provides stairway access and will serve as my terrarium.
|Stairway to the first floor|
|Vines provide access to the upper levels|
|Storage area, somewhat organized|
|My penthouse bedroom|
|View from the bedroom of my farm,|
still a work in process
|That flat hill is just begging for|
a castle, fort, or some such thing...