I really like the theme. I think that making the characters share control over a single character is an interesting choice that hopefully keeps everyone really in tune with each turn as what one player does with their has a big impact on each other players potential actions.
The round structure is an interesting twist in that it feels like it adds a slightly competitive aspect to determining turn order. I've seen a few games do one big threat roll at the top of a round. Maybe you could use that to great effect as every character inhabits the same body.
I do think that there may be room to add additional objectives or pressure. Right now it seems like there aren't many decisions to make with your beyond protecting yourself and pushing the main objective. Bamboo Forest is closer to what I think you could do with all areas after the first one (to keep things simple for the first scene).
Also this is a sight nitpick but I'm assuming the x by some objectives and threats is difficulty. I saw difficulty mentioned once but not sure I saw how you represented it on the page explained.
Last note, I love the haikus on the character sheets.