Super Mario Galaxy 2 - Boo Moon Galaxy (Boo Mario)

After getting lost for hours Mario finally stumbles upon a mushroom that turns him into a Boo. Exciting, isn't it? The feel of this level seems like it could possibly be an homage to the paper mario games. It is more evident when getting the other star for this galaxy because you actually go outside. Theres also a "pop up" part of the level you need to collect silver stars on, but it could be just me looking too deep into it.