* Climbing a ladder: Those slippery soles would make it nearly impossible to get a grip on the rungs.
* Running a marathon: Glass isn't exactly the most comfortable or supportive material for long distances.
* Playing soccer: Imagine trying to kick a ball while wearing glass slippers!
* Hiking in the mountains: Those delicate slippers would quickly shatter on uneven terrain.
* Working in the garden: Digging in the dirt with glass slippers would be a recipe for disaster (and cut feet).
* Dancing on a cobblestone street: The uneven surface would make it difficult to walk, let alone dance.
* Walking on the beach: Sand would get trapped inside the slippers, making them uncomfortable and difficult to walk in.
Let me know if you want more ideas!