Kids design at its most simple - let the kids create the use of the object. Like the amazing lure of another multi-use fun thing, Silly Putty, the Bilibo is all about open ended play.
It is a hat, a rocking chair, a shovel, a bucket, a box, a cradle, a hill, a tunnel, a cave, a drum, a hiding place. Or it's just a $28. piece of plastic, if you are a stodgy grown-up.
This multi-tasking wonder won't even take up much room in the toy storage area, a bonus for apartment dwelling families. 
I can see lots of kids falling or slipping off this when it is a 'hill'...major liability issues!
i can see lots of kids falling off it once or twice when it's a "hill" and then realizing that hurts and not using it as a "hill" anymore.
geez...