They were all good ideas, anyway, now we have to decide which one we're going to go with.
That's a good question. I hadn't thought of that. I think if we have time later, we could make the player descend down and go from one area to another.
But I think we should start with a vibrant dungeon. Like a dungeon that is being lived in. With wooden rafters and stuff.
The next area could be a darker abandoned dungeon.
And maybe a demonic layer for the third level?
Also perhaps hidden bonus areas could be made of caves?